Re: Getting NullPointerException while executing query
I am using cassandra 1.2.0,
Thanks
Kuldeep
On Wed, Apr 10, 2013 at 10:40 PM, Sylvain Lebresne sylv...@datastax.comwrote:
On which version of Cassandra are you? I can't reproduce the
NullPointerException on Cassandra 1.2.3.
That being said, that query is not valid, so you will get an error
message. There is 2 reasons why it's not valid:
1) in token(deep), deep is not a valid term. So you should have
something like: token('deep').
2) the name column is not the partition key so the token method cannot
be applied to it.
A valid query with that schema would be for instance:
select * from CQLUSER where token(id) token(4)
though I don't know if that help in any way for what you aimed to do.
--
Sylvain
On Wed, Apr 10, 2013 at 9:42 AM, Kuldeep Mishra
kuld.cs.mis...@gmail.comwrote:
Hi ,
TABLE -
CREATE TABLE CQLUSER (
id int PRIMARY KEY,
age int,
name text
)
Query -
select * from CQLUSER where token(name) token(deep);
ERROR -
Bad Request: Failed parsing statement: [select * from CQLUSER where
token(name) token(deep);] reason: NullPointerException null
text could not be lexed at line 1, char 15
--
Thanks and Regards
Kuldeep Kumar Mishra
+919540965199
--
Thanks and Regards
Kuldeep Kumar Mishra
+919540965199
Re: Added column does not sort as the last column at
To reduce possibilities, have you changed a super CF to a standard CF recently ? Can you isolate this to specific CF ? Have you changed the comparators / schema recently ? Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 1:26 AM, Sam Hodgson hodgson_...@hotmail.com wrote: Hi All, I just upgraded from Cassandra 1.1.7 to 1.2.3 and im now seeing a lot of the following error in my output.log, cant find much on the web about it: ERROR 11:56:01,317 Exception in thread Thread[ReadStage:7236,5,main] java.lang.AssertionError: Added column does not sort as the last column at org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:131) at org.apache.cassandra.db.AbstractColumnContainer.addColumn(AbstractColumnContainer.java:109) at org.apache.cassandra.db.AbstractColumnContainer.addColumn(AbstractColumnContainer.java:104) at org.apache.cassandra.db.filter.SliceQueryFilter.collectReducedColumns(SliceQueryFilter.java:171) at org.apache.cassandra.db.filter.QueryFilter.collateColumns(QueryFilter.java:136) at org.apache.cassandra.db.filter.QueryFilter.collateOnDiskAtom(QueryFilter.java:84) at org.apache.cassandra.db.CollationController.collectAllData(CollationController.java:294) at org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:65) at org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1363) at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1220) at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1132) at org.apache.cassandra.db.Table.getRow(Table.java:348) at org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:70) at org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:1052) at org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1578) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662) I dont know Java and im struggling to identify exactly which query is causing this, is there a way to trace this back to a specific query? Any help appreciated. Sam
Re: Column index vs Row index vs Denormalizing
Retrieving the latest 1000 tweets (of a given day) is trivial by requesting the streamTweets columnFamily. If you normally want to get the most recent items use a reverse comparator on the column name see http://thelastpickle.com/2011/10/03/Reverse-Comparators/ Getting the latest tweets for a given hashtag would mean you have to get the TimeUUIDs from the streamHashTagTweets first, and then do a second get call on the streamTweets with the former TimeUUIDs as the list of columns we like to retrieve (column index). You choices here depend on what sort of queries are the most frequent and how much disk space you have. You current model makes sense if the stream by day is the most frequent query, and you want to conserve disk space. If disk space is not an issue you can denormalise further and store the tweet JSON. If you have potentially many streamHashTagTweets rows where a single tweet is replicated it may make sense to stick with the current design to reduce disk use. (we want to get up to 1000 tweets). If you want to get 1000 anything from cassandra please break the multiget up into multiple calls. Each row request becomes a task in the thread pools on RF nodes. If you have a small ish cluster one client asking for 1000 rows will temporarily block other clients and hurt request throughput. Referencing key values requires another columnFamily for tweets (key: tweetId, columns: 1 column with data). This will be a more efficient (aka faster) read than reading from the a wide row. Next to that we will request tweets by these secondary indexes quite infrequently, while the tweets by timestamp will be requested heavily. If the hot path is the streamTweets calls demoralise into that, and normalise the tweet storage into it's own CF and reference them from the streamHashTagTweets. Have a canonical store of the events / tweets / entities addressable by their business key can give you more flexibility. Given we are estimating to store many TBs of tweets, we would prefer setting up machines with spinning disks (2TB per node) to save costs. If you have spinning disks and 1G networking the rule of thumb is 300GB to 500GB per node. See previous discussions about size per node. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 2:00 AM, Coen Stevens beatle...@gmail.com wrote: Hi all, We are working on a data model for storing tweets for multiple streams (where a stream is defined by a number of keyword filters on the full twitter firehose), and retrieving the tweets by timestamp and hashtag. My question is whether the following data model would a good way for doing that, where I'm creating a column name index for the hashtags. ColumnFamily: streamTweets key: streamID + dayTimestamp (creating daily buckets for each stream) columns = name: TimeUUID, value: tweet json (storing all the tweets for this stream in a wide row with a TimeUUID) ColumnFamily: streamHashTagTweets key: streamID + dayTimestamp + hashTag (e.g. 123_2013-04-02_cassandra) columns = name: TimeUUID (referencing the TimeUUID value in the streamTweets ColumnFamily), value: tweetID Retrieving the latest 1000 tweets (of a given day) is trivial by requesting the streamTweets columnFamily. Getting the latest tweets for a given hashtag would mean you have to get the TimeUUIDs from the streamHashTagTweets first, and then do a second get call on the streamTweets with the former TimeUUIDs as the list of columns we like to retrieve (column index). Is referencing column names (TimeUUIDs) a smart thing to do when we have wide rows spanning millions of columns? It seems easier (one reference call) to do this, then it is to reference key values and running a multi-get to get all the rows (we want to get up to 1000 tweets). Referencing key values requires another columnFamily for tweets (key: tweetId, columns: 1 column with data). Of course we could instead denormalize the data and store the tweet also in the streamHashTagTweet columns, but we want to do the same thing for other indexes as well (topics, twitter usernames, links, etc), so it quickly adds up in required storage space. Next to that we will request tweets by these secondary indexes quite infrequently, while the tweets by timestamp will be requested heavily. Given we are estimating to store many TBs of tweets, we would prefer setting up machines with spinning disks (2TB per node) to save costs. We would love to hear your feedback. Cheers, Coen
Re: data modeling from batch_mutate point of view
b) the batch_mutate advantages are better, for the communication client=coordinator node __and__ for the communications coordinator node=replicas. Yes. A single row mutation can write to many CFs. Is there any experience out there about such data modeling (option_a vs option_b) from the batch_mutate perspective ? Thanks. I would not worry about the internal network lag as much as creating hot rows in the model. Sometimes it makes sense for an entity to map to rows in several CF's that use the same key, e.g. user info or a blog post. However it is normally bad when many entities require storing data on the same row, e.g. all blog posts have to update one row. From my understanding of what you are doing I would look to spread out the index entries to use different row keys. If the indexes are small you may get away with using the same key, but I would start with spreading it out. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 2:27 AM, DE VITO Dominique dominique.dev...@thalesgroup.com wrote: Thanks Aaron. It helped. Let's me rephrase a little bit my questions. It's about data modeling impact on batch_mutate advantages. I have one CF for storing data, and ~10 (all different) CF used for indexing that data. when adding a piece of data, I need to add indexes too, and then, I need to add columns to one row for each of the 10 indexing CF = 2 main designs are possible for adding these new indexes. a) all the updated 10 rows of indexing CF have different rowkeys b) all the updated 10 rows of indexing CF have all the same rowkey AFAIK, this has effect on batch_mutate: a) the batch_mutate advantages stop at the coordinator node. The advantage appears for the communication client=coordinator node b) the batch_mutate advantages are better, for the communication client=coordinator node __and__ for the communications coordinator node=replicas. So, for resuming: a) CF with few data repeats (good) but the coordinator node needs to communicate to different replicas according to different rowkeys b) CF with more denormalization, repeating some data, again and again over composite columns, but batch_mutate performs better (good) up to replicas, and not only up to coordinator node. Each option has one pro and one con. Is there any experience out there about such data modeling (option_a vs option_b) from the batch_mutate perspective ? Thanks. Dominique De : aaron morton [mailto:aa...@thelastpickle.com] Envoyé : mardi 9 avril 2013 10:12 À : user@cassandra.apache.org Objet : Re: data modeling from batch_mutate point of view So, one alternative design for indexing CF could be: rowkey = folder_id colname = (indexed value, timestamp, file_id) colvalue = If you always search in a folder what about rowkey = folder_id : property_name : property_value colname = file_id (That's closer to secondary indexes in cassandra with the addition of the folder_id) According to pro vs con, is the alternative design more or less interesting ? IMHO it's normally better to spread the rows and consider how they grow over time. You can send updates for multiple rows in the same batch mutation. Hope that helps. - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 9/04/2013, at 3:57 AM, DE VITO Dominique dominique.dev...@thalesgroup.com wrote: Hi, I have a use case that sounds like storing data associated with files. So, I store them with the CF: rowkey = (folder_id, file_id) colname = property name (about the file corresponding to file_id) colvalue = property value And I have CF for manual indexing: rowkey = (folder_id, indexed value) colname = (timestamp, file_id) colvalue = like rowkey = (folder_id, note_of_5) or (folder_id, some_status) colname = (some_date, some_filename) colvalue = I have many CF for indexing, as I index according to different (file) properties. So, one alternative design for indexing CF could be: rowkey = folder_id colname = (indexed value, timestamp, file_id) colvalue = Alternative design : * pro: same rowkey for all indexing CF = **all** indexing CF could be updated through one batch_mutate * con: repeating indexed value (1er colname part) again ang again (= a string up to 20c) According to pro vs con, is the alternative design more or less interesting ? Thanks. Dominique
Re: other questions about // RE: batch_mutate
Is it true the coordinator node treats them as __independent__ communications/requests to replicas (even if in that case, the replicas are the same for every request) ? A row mutation is a request to store columns in one or more CF's using one row key. It is treated as indivisible by the commit log and a single message is sent to each replica that contains all the CF updates. When the mutation is applied it is applied to each CF in turn, and the row level isolation does not apply across CF's. I assume your them is the many CF's the row mutation updates, if so the answer is no. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 3:26 AM, DE VITO Dominique dominique.dev...@thalesgroup.com wrote: When the coordinator node receives a batch_mutate for __one__ row key associated with different mutations for different CF : Is it true the coordinator node treats them as __independent__ communications/requests to replicas (even if in that case, the replicas are the same for every request) ? Thanks, Dominique De : aaron morton [mailto:aa...@thelastpickle.com] Envoyé : vendredi 6 juillet 2012 01:21 À : user@cassandra.apache.org Objet : Re: batch_mutate Does it mean that the popular use case is when we need to update multiple column families using the same key? Yes. Shouldn’t we design our space in such a way that those columns live in the same column family? Design a model where the data for common queries is stored in one row+cf. You can also take into consideration the workload. e.g. things are are updated frequently often live together, things that are updated infrequently often live together. cheers - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 6/07/2012, at 3:16 AM, Leonid Ilyevsky wrote: I actually found an answer to my first question at http://wiki.apache.org/cassandra/API. So I got it wrong: actually the outer key is the key in the table, and the inner key is the table name (this was somewhat counter-intuitive). Does it mean that the popular use case is when we need to update multiple column families using the same key? Shouldn’t we design our space in such a way that those columns live in the same column family? From: Leonid Ilyevsky [mailto:lilyev...@mooncapital.com] Sent: Thursday, July 05, 2012 10:39 AM To: 'user@cassandra.apache.org' Subject: batch_mutate My current way of inserting rows one by one is too slow (I use cql3 prepared statements) , so I want to try batch_mutate. Could anybody give me more details about the interface? In the javadoc it says: public voidbatch_mutate(java.util.Mapjava.nio.ByteBuffer,java.util.Mapjava.lang.String,java.util.ListMutation mutation_map, ConsistencyLevel consistency_level) throws InvalidRequestException, UnavailableException, TimedOutException, org.apache.thrift.TException Description copied from interface: Cassandra.Iface Mutate many columns or super columns for many row keys. See also: Mutation. mutation_map maps key to column family to a list of Mutation objects to take place at that scope. * I need to understand the meaning of the elements of mutation_map parameter. My guess is, the key in the outer map is columnfamily name, is this correct? The key in the inner map is, probably, a key to the columnfamily (it is somewhat confusing that it is String while the outer key is ByteBuffer, I wonder what is the rational). If this is correct, how should I do it if my key is a composite one. Does anybody have an example? Thanks, Leonid This email, along with any attachments, is confidential and may be legally privileged or otherwise protected from disclosure. Any unauthorized dissemination, copying or use of the contents of this email is strictly prohibited and may be in violation of law. If you are not the intended recipient, any disclosure, copying, forwarding or distribution of this email is strictly prohibited and this email and any attachments should be deleted immediately. This email and any attachments do not constitute an offer to sell or a solicitation of an offer to purchase any interest in any investment vehicle sponsored by Moon Capital Management LP (“Moon Capital”). Moon Capital does not provide legal, accounting or tax advice. Any statement regarding legal, accounting or tax matters was not intended or written to be relied upon by any person as advice. Moon Capital does not waive confidentiality or privilege as a result of this email. This email, along with any attachments, is confidential and may be legally privileged or otherwise protected from disclosure. Any unauthorized dissemination, copying or use of
Re: Cassandra 1.2.2 cluster + raspberry
I've already tried to set internode_compression: none in my yaml files. What version are you on? If you've set internode_compression to none and restarted? Can you double check. The code stack shows cassandra deciding that the connection should be compressed. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 12:54 PM, murat migdisoglu murat.migdiso...@gmail.com wrote: Hi, I'm trying to set up a cassandra cluster for some experiments on my raspberry pies but I'm still having trouble to join my nodes to the cluster. I started with two nodes (192.168.2.3 and 192.168.2.7) and when I start the cassandra, I see the following exception on the node 192.168.2.7 ERROR [WRITE-/192.168.2.3] 2013-04-10 02:10:24,524 CassandraDaemon.java (line 132) Exception in thread Thread[WRITE-/192.168.2.3,5,main] java.lang.NoClassDefFoundError: Could not initialize class org.xerial.snappy.Snappy at org.xerial.snappy.SnappyOutputStream.init(SnappyOutputStream.java:79) at org.xerial.snappy.SnappyOutputStream.init(SnappyOutputStream.java:66) at org.apache.cassandra.net.OutboundTcpConnection.connect(OutboundTcpConnection.java:322) at org.apache.cassandra.net.OutboundTcpConnection.run(OutboundTcpConnection.java:143) I suspect that the lack of native snappy libraries are causing this exception furing the internode communication. I did not try to compile the native Snappy for ARM yet but I wonder if it is not possible to use cassandra without snappy. I've already tried to set internode_compression: none in my yaml files. nodetool outputs: nodetool -h pi1 ring Datacenter: dc1 == Replicas: 1 Address RackStatus State LoadOwns Token 192.168.2.7 RAC1Up Normal 92.35 KB100.00% 0 nodetool -h pi2 ring Datacenter: dc1 == Replicas: 1 Address RackStatus State LoadOwns Token 192.168.2.3 RAC1Up Normal 92.42 KB100.00% 85070591730234615865843651857942052864 Kind Regards
Re: CDH4 + Cassandra 1.2 Integration Issue
cqlsh in cassandra 1.2 defaults to cql 3.
-
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 10/04/2013, at 6:55 PM, Gurminder Gill gurminde...@hotmail.com wrote:
Ah ha. So, the client defaults to CQL 2. Anyway of changing that? I tired
libthrift 0.9 as well but it doesn't work.
Thanks.
On Tue, Apr 9, 2013 at 11:29 PM, Shamim sre...@yandex.ru wrote:
Hello,
if you created your table user with cql then you have to add COMPACT
STORAGE as follows:
CREATE TABLE user (
id int PRIMARY KEY,
age int,
fname text,
lname text
) WITH COMPACT STORAGE
--
Best regards
Shamim A.
10.04.2013, 08:22, Gurminder Gill gurminde...@hotmail.com:
I was able to start a MR job after patching Cassandra.Hadoop as per
CASSANDRA-5201.
But then, ColumnFamilyRecordReader pukes within the MapTask. It is unable
to read CF definition in the sample keyspace. The CF user does exist.
How can cf_defs below be possibly empty? Any pointers?
KsDef.toString() during Read Operation from within the MapTask :-
KsDef(name:wordcount,
strategy_class:org.apache.cassandra.locator.SimpleStrategy,
strategy_options:{replication_factor=1}, cf_defs:[], durable_writes:true)
Output from cqlsh :-
cqlsh describe keyspace wordcount;
CREATE KEYSPACE wordcount WITH replication = {
'class': 'SimpleStrategy',
'replication_factor': '1'
};
USE wordcount;
CREATE TABLE user (
id int PRIMARY KEY,
age int,
fname text,
lname text
) WITH
bloom_filter_fp_chance=0.01 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.00 AND
gc_grace_seconds=864000 AND
read_repair_chance=0.10 AND
replicate_on_write='true' AND
compaction={'class': 'SizeTieredCompactionStrategy'} AND
compression={'sstable_compression': 'SnappyCompressor'};
Re: Blobs in CQL?
Hi Brian, I'm using the blobs to store images in cassandra(1.2.3) using the java-driver version 1.0.0-beta1. There is no need to convert a byte array into hex. Br, Gabi On 4/11/13 3:21 PM, Brian O'Neill wrote: I started playing around with the CQL driver. Has anyone used blobs with it yet? Are you forced to convert a byte[] to hex? (e.g. I have a photo that I want to store in C* using the java-driver API) -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience.com) mobile:215.588.6024 blog: http://brianoneill.blogspot.com/ twitter: @boneill42
Re: Blobs in CQL?
Great! Thanks Gabriel. Do you have an example? (are using QueryBuilder?) I couldn't find the part of the API that allowed you to pass in the byte array. -brian --- Brian O'Neill Lead Architect, Software Development Health Market Science The Science of Better Results 2700 Horizon Drive King of Prussia, PA 19406 M: 215.588.6024 @boneill42 http://www.twitter.com/boneill42 healthmarketscience.com This information transmitted in this email message is for the intended recipient only and may contain confidential and/or privileged material. If you received this email in error and are not the intended recipient, or the person responsible to deliver it to the intended recipient, please contact the sender at the email above and delete this email and any attachments and destroy any copies thereof. Any review, retransmission, dissemination, copying or other use of, or taking any action in reliance upon, this information by persons or entities other than the intended recipient is strictly prohibited. On 4/11/13 8:25 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote: Hi Brian, I'm using the blobs to store images in cassandra(1.2.3) using the java-driver version 1.0.0-beta1. There is no need to convert a byte array into hex. Br, Gabi On 4/11/13 3:21 PM, Brian O'Neill wrote: I started playing around with the CQL driver. Has anyone used blobs with it yet? Are you forced to convert a byte[] to hex? (e.g. I have a photo that I want to store in C* using the java-driver API) -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience.com) mobile:215.588.6024 blog: http://brianoneill.blogspot.com/ twitter: @boneill42
Re: Blobs in CQL?
I'm not using the query builder but the PreparedStatement. Here is the sample code: https://gist.github.com/devsprint/5363023 Gabi On 4/11/13 3:27 PM, Brian O'Neill wrote: Great! Thanks Gabriel. Do you have an example? (are using QueryBuilder?) I couldn't find the part of the API that allowed you to pass in the byte array. -brian --- Brian O'Neill Lead Architect, Software Development Health Market Science The Science of Better Results 2700 Horizon Drive € King of Prussia, PA € 19406 M: 215.588.6024 € @boneill42 http://www.twitter.com/boneill42 € healthmarketscience.com This information transmitted in this email message is for the intended recipient only and may contain confidential and/or privileged material. If you received this email in error and are not the intended recipient, or the person responsible to deliver it to the intended recipient, please contact the sender at the email above and delete this email and any attachments and destroy any copies thereof. Any review, retransmission, dissemination, copying or other use of, or taking any action in reliance upon, this information by persons or entities other than the intended recipient is strictly prohibited. On 4/11/13 8:25 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote: Hi Brian, I'm using the blobs to store images in cassandra(1.2.3) using the java-driver version 1.0.0-beta1. There is no need to convert a byte array into hex. Br, Gabi On 4/11/13 3:21 PM, Brian O'Neill wrote: I started playing around with the CQL driver. Has anyone used blobs with it yet? Are you forced to convert a byte[] to hex? (e.g. I have a photo that I want to store in C* using the java-driver API) -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience.com) mobile:215.588.6024 blog: http://brianoneill.blogspot.com/ twitter: @boneill42
Re: Blobs in CQL?
Cool. That might be it. I'll take a look at PreparedStatement.
For query building, I took a look under the covers, and even when I was
passing in a ByteBuffer, it runs through the following code in the
java-driver:
Utils.java:
if (value instanceof ByteBuffer) {
sb.append(0x);
sb.append(ByteBufferUtil.bytesToHex((ByteBuffer)value));
}
Hopefully, the prepared statement doesn't do the conversion.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
I'm not using the query builder but the PreparedStatement.
Here is the sample code: https://gist.github.com/devsprint/5363023
Gabi
On 4/11/13 3:27 PM, Brian O'Neill wrote:
Great!
Thanks Gabriel. Do you have an example? (are using QueryBuilder?)
I couldn't find the part of the API that allowed you to pass in the
byte
array.
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive € King of Prussia, PA € 19406
M: 215.588.6024 € @boneill42 http://www.twitter.com/boneill42 €
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material.
If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:25 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
Hi Brian,
I'm using the blobs to store images in cassandra(1.2.3) using the
java-driver version 1.0.0-beta1.
There is no need to convert a byte array into hex.
Br,
Gabi
On 4/11/13 3:21 PM, Brian O'Neill wrote:
I started playing around with the CQL driver.
Has anyone used blobs with it yet?
Are you forced to convert a byte[] to hex?
(e.g. I have a photo that I want to store in C* using the java-driver
API)
-brian
--
Brian ONeill
Lead Architect, Health Market Science (http://healthmarketscience.com)
mobile:215.588.6024
blog: http://brianoneill.blogspot.com/
twitter: @boneill42
Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion. It does not. (I'm not sure if it is a limitation of the CQL protocol itself) thanks again, -brian --- Brian O'Neill Lead Architect, Software Development Health Market Science The Science of Better Results 2700 Horizon Drive • King of Prussia, PA • 19406 M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 • healthmarketscience.com This information transmitted in this email message is for the intended recipient only and may contain confidential and/or privileged material. If you received this email in error and are not the intended recipient, or the person responsible to deliver it to the intended recipient, please contact the sender at the email above and delete this email and any attachments and destroy any copies thereof. Any review, retransmission, dissemination, copying or other use of, or taking any action in reliance upon, this information by persons or entities other than the intended recipient is strictly prohibited. On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote: I'm not using the query builder but the PreparedStatement. Here is the sample code: https://gist.github.com/devsprint/5363023 Gabi On 4/11/13 3:27 PM, Brian O'Neill wrote: Great! Thanks Gabriel. Do you have an example? (are using QueryBuilder?) I couldn't find the part of the API that allowed you to pass in the byte array. -brian --- Brian O'Neill Lead Architect, Software Development Health Market Science The Science of Better Results 2700 Horizon Drive € King of Prussia, PA € 19406 M: 215.588.6024 € @boneill42 http://www.twitter.com/boneill42 € healthmarketscience.com This information transmitted in this email message is for the intended recipient only and may contain confidential and/or privileged material. If you received this email in error and are not the intended recipient, or the person responsible to deliver it to the intended recipient, please contact the sender at the email above and delete this email and any attachments and destroy any copies thereof. Any review, retransmission, dissemination, copying or other use of, or taking any action in reliance upon, this information by persons or entities other than the intended recipient is strictly prohibited. On 4/11/13 8:25 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote: Hi Brian, I'm using the blobs to store images in cassandra(1.2.3) using the java-driver version 1.0.0-beta1. There is no need to convert a byte array into hex. Br, Gabi On 4/11/13 3:21 PM, Brian O'Neill wrote: I started playing around with the CQL driver. Has anyone used blobs with it yet? Are you forced to convert a byte[] to hex? (e.g. I have a photo that I want to store in C* using the java-driver API) -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience.com ) mobile:215.588.6024 blog: http://brianoneill.blogspot.com/ twitter: @boneill42
multiple Datacenter values in PropertyFileSnitch
Hi, I would like to create big cluster for many applications. Within this cluster I would like to separate the data for each application, which can be easily done via different virtual datacenters and the correct replication strategy. What I would like to know, if I can specify for 1 node multiple values in the PropertyFileSnitch configuration, so that I can use 1 node for more applications? For example: 6 nodes: 3 for App A 3 for App B 4 for App C I want to have such a configuration: Node 1 - DC-A DC-C Node 2 - DC-B DC-C Node 3 - DC-A DC-C Node 4 - DC-B DC-C Node 5 - DC-A Node 6 - DC-B Is this possible or does anyone have another solution for this? Thx br matthias
Re: Blobs in CQL?
Yep, it worked like a charm. (PreparedStatement avoided the hex conversion)
But now, I'm seeing a few extra bytes come back in the select….
(I'll keep digging, but maybe you have some insight?)
I see this:
ERROR [2013-04-11 13:05:03,461] com.skookle.dao.RepositoryDao:
repository.add() byte.length()=[259804]
ERROR [2013-04-11 13:08:08,487] com.skookle.dao.RepositoryDao:
repository.get() [foo.jpeg] byte.length()=[259861]
(Notice the length's don't match up)
Using this code:
public void addContent(String key, byte[] data)
throws NoHostAvailableException {
LOG.error(repository.add() byte.length()=[ + data.length + ]);
String statement = INSERT INTO + KEYSPACE + . + TABLE + (key,
data) VALUES (?, ?);
PreparedStatement ps = session.prepare(statement);
BoundStatement bs = ps.bind(key, ByteBuffer.wrap(data));
session.execute(bs);
}
public byte[] getContent(String key) throws NoHostAvailableException {
Query select = select(data).from(KEYSPACE, TABLE).where(eq(key,
key));
ResultSet resultSet = session.execute(select);
byte[] data = resultSet.one().getBytes(data).array();
LOG.error(repository.get() [ + key + ] byte.length()=[ +
data.length + ]);
return data;
}
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or the
person responsible to deliver it to the intended recipient, please contact
the sender at the email above and delete this email and any attachments and
destroy any copies thereof. Any review, retransmission, dissemination,
copying or other use of, or taking any action in reliance upon, this
information by persons or entities other than the intended recipient is
strictly prohibited.
From: Sylvain Lebresne sylv...@datastax.com
Reply-To: user@cassandra.apache.org
Date: Thursday, April 11, 2013 8:48 AM
To: user@cassandra.apache.org user@cassandra.apache.org
Cc: Gabriel Ciuloaica gciuloa...@gmail.com
Subject: Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion.
It does not.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 tel:215.588.6024 • @boneill42
http://www.twitter.com/boneill42 •
healthmarketscience.com http://healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
I'm not using the query builder but the PreparedStatement.
Here is the sample code: https://gist.github.com/devsprint/5363023
Gabi
On 4/11/13 3:27 PM, Brian O'Neill wrote:
Great!
Thanks Gabriel. Do you have an example? (are using QueryBuilder?)
I couldn't find the part of the API that allowed you to pass in the
byte
array.
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive € King of Prussia, PA € 19406
M: 215.588.6024 tel:215.588.6024 € @boneill42
http://www.twitter.com/boneill42 €
healthmarketscience.com http://healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material.
If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:25 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
Hi Brian,
I'm using
Re: Blobs in CQL?
Sylvain,
Interesting, when I look at the actual bytes returned, I see the byte array
is prefixed with the keyspace and table name.
I assume I'm doing something wrong in the select. Am I incorrectly using
the ResultSet?
-brian
On Thu, Apr 11, 2013 at 9:09 AM, Brian O'Neill b...@alumni.brown.eduwrote:
Yep, it worked like a charm. (PreparedStatement avoided the hex
conversion)
But now, I'm seeing a few extra bytes come back in the select….
(I'll keep digging, but maybe you have some insight?)
I see this:
ERROR [2013-04-11 13:05:03,461] com.skookle.dao.RepositoryDao:
repository.add() byte.length()=[259804]
ERROR [2013-04-11 13:08:08,487] com.skookle.dao.RepositoryDao:
repository.get() [foo.jpeg] byte.length()=[259861]
(Notice the length's don't match up)
Using this code:
public void addContent(String key, byte[] data)
throws NoHostAvailableException {
LOG.error(repository.add() byte.length()=[ + data.length + ]);
String statement = INSERT INTO + KEYSPACE + . + TABLE + (key,
data) VALUES (?, ?);
PreparedStatement ps = session.prepare(statement);
BoundStatement bs = ps.bind(key, ByteBuffer.wrap(data));
session.execute(bs);
}
public byte[] getContent(String key) throws NoHostAvailableException {
Query select = select(data).from(KEYSPACE, TABLE).where(eq(key,
key));
ResultSet resultSet = session.execute(select);
byte[] data = resultSet.one().getBytes(data).array();
LOG.error(repository.get() [ + key + ] byte.length()=[ + data.
length + ]);
return data;
}
---
Brian O'Neill
Lead Architect, Software Development
*Health Market Science*
*The Science of Better Results*
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or the
person responsible to deliver it to the intended recipient, please contact
the sender at the email above and delete this email and any attachments and
destroy any copies thereof. Any review, retransmission, dissemination,
copying or other use of, or taking any action in reliance upon, this
information by persons or entities other than the intended recipient is
strictly prohibited.
** **
From: Sylvain Lebresne sylv...@datastax.com
Reply-To: user@cassandra.apache.org
Date: Thursday, April 11, 2013 8:48 AM
To: user@cassandra.apache.org user@cassandra.apache.org
Cc: Gabriel Ciuloaica gciuloa...@gmail.com
Subject: Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion.
It does not.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
I'm not using the query builder but the PreparedStatement.
Here is the sample code: https://gist.github.com/devsprint/5363023
Gabi
On 4/11/13 3:27 PM, Brian O'Neill wrote:
Great!
Thanks Gabriel. Do you have an example? (are using QueryBuilder?)
I couldn't find the part of the API that allowed you to pass in the
byte
array.
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive € King of Prussia, PA € 19406
M: 215.588.6024 € @boneill42 http://www.twitter.com/boneill42 €
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material.
If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or
Re: Blobs in CQL?
That's right, there is some padding there...
So, instead of getting calling array(), you have to do something like:
byte[] data = resultSet.one().getBytes(data);
int length = data.remaining();
blobBytes = new byte[length];
data.get(blobBytes, 0, length);
Gabi
On 4/11/13 4:09 PM, Brian O'Neill wrote:
Yep, it worked like a charm. (PreparedStatement avoided the hex
conversion)
But now, I'm seeing a few extra bytes come back in the select….
(I'll keep digging, but maybe you have some insight?)
I see this:
ERROR [2013-04-11 13:05:03,461] com.skookle.dao.RepositoryDao:
repository.add() byte.length()=[259804]
ERROR [2013-04-11 13:08:08,487] com.skookle.dao.RepositoryDao:
repository.get() [foo.jpeg] byte.length()=[259861]
(Notice the length's don't match up)
Using this code:
public void addContent(String key, byte[] data)
throws NoHostAvailableException {
LOG.error(repository.add() byte.length()=[+ data.length+ ]);
String statement = INSERT INTO + KEYSPACE+ .+ TABLE+ (key,
data) VALUES (?, ?);
PreparedStatement ps = session.prepare(statement);
BoundStatement bs = ps.bind(key, ByteBuffer.wrap(data));
session.execute(bs);
}
public byte[] getContent(String key) throws NoHostAvailableException {
Query select = select(data).from(KEYSPACE,
TABLE).where(eq(key, key));
ResultSet resultSet = session.execute(select);
byte[] data = resultSet.one().getBytes(data).array();
LOG.error(repository.get() [+ key + ] byte.length()=[+
data.length+ ]);
return data;
}
---
Brian O'Neill
Lead Architect, Software Development
*Health Market Science*
/The Science of Better Results/
2700 Horizon Drive •King of Prussia, PA •19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged
material. If you received this email in error and are not the intended
recipient, or the person responsible to deliver it to the intended
recipient, please contact the sender at the email above and delete
this email and any attachments and destroy any copies thereof. Any
review, retransmission, dissemination, copying or other use of, or
taking any action in reliance upon, this information by persons or
entities other than the intended recipient is strictly prohibited.
From: Sylvain Lebresne sylv...@datastax.com
mailto:sylv...@datastax.com
Reply-To: user@cassandra.apache.org mailto:user@cassandra.apache.org
Date: Thursday, April 11, 2013 8:48 AM
To: user@cassandra.apache.org mailto:user@cassandra.apache.org
user@cassandra.apache.org mailto:user@cassandra.apache.org
Cc: Gabriel Ciuloaica gciuloa...@gmail.com mailto:gciuloa...@gmail.com
Subject: Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion.
It does not.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 tel:215.588.6024 • @boneill42
http://www.twitter.com/boneill42 •
healthmarketscience.com http://healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged
material. If
you received this email in error and are not the intended
recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review,
retransmission,
dissemination, copying or other use of, or taking any action in
reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com
mailto:gciuloa...@gmail.com wrote:
I'm not using the query builder but the PreparedStatement.
Here is the sample code: https://gist.github.com/devsprint/5363023
Gabi
On 4/11/13 3:27 PM, Brian O'Neill wrote:
Great!
Thanks Gabriel. Do you have an example? (are using QueryBuilder?)
I couldn't find the part of the API that allowed you to pass
in the
byte
array.
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive € King of Prussia, PA € 19406
M: 215.588.6024 tel:215.588.6024 € @boneill42
http://www.twitter.com/boneill42 €
healthmarketscience.com http://healthmarketscience.com
This information transmitted in this email message is for the
intended
recipient only and may contain confidential and/or
Re: Blobs in CQL?
I assume I'm doing something wrong in the select. Am I incorrectly using
the ResultSet?
You're incorrectly using the returned ByteBuffer. But you should not feel
bad, that API kinda
sucks.
The short version is that .array() returns the backing array of the
ByteBuffer. But there is no
guarantee that you'll have a one-to-one correspondence between the valid
content of the
ByteBuffer and the backing array, the backing array can be bigger in
particular (long story short,
this allows multiple ByteBuffer to share the same backing array, which can
avoid doing copies).
I also note that there is no guarantee that .array() will work unless
you've called .hasArray().
Anyway, what you could do is:
ByteBuffer bb = resultSet.one().getBytes(data);
byte[] data = new byte[bb.remaining()];
bb.get(data);
Alternatively, you can use the result of .array(), but you should only
consider the bb.remaining()
bytes starting at bb.arrayOffset() + bb.position() (where bb is the
returned ByteBuffer).
--
Sylvain
-brian
On Thu, Apr 11, 2013 at 9:09 AM, Brian O'Neill b...@alumni.brown.eduwrote:
Yep, it worked like a charm. (PreparedStatement avoided the hex
conversion)
But now, I'm seeing a few extra bytes come back in the select….
(I'll keep digging, but maybe you have some insight?)
I see this:
ERROR [2013-04-11 13:05:03,461] com.skookle.dao.RepositoryDao:
repository.add() byte.length()=[259804]
ERROR [2013-04-11 13:08:08,487] com.skookle.dao.RepositoryDao:
repository.get() [foo.jpeg] byte.length()=[259861]
(Notice the length's don't match up)
Using this code:
public void addContent(String key, byte[] data)
throws NoHostAvailableException {
LOG.error(repository.add() byte.length()=[ + data.length + ]
);
String statement = INSERT INTO + KEYSPACE + . + TABLE + (key,
data) VALUES (?, ?);
PreparedStatement ps = session.prepare(statement);
BoundStatement bs = ps.bind(key, ByteBuffer.wrap(data));
session.execute(bs);
}
public byte[] getContent(String key) throws NoHostAvailableException
{
Query select = select(data).from(KEYSPACE, TABLE).where(eq(
key, key));
ResultSet resultSet = session.execute(select);
byte[] data = resultSet.one().getBytes(data).array();
LOG.error(repository.get() [ + key + ] byte.length()=[ +
data.length + ]);
return data;
}
---
Brian O'Neill
Lead Architect, Software Development
*Health Market Science*
*The Science of Better Results*
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or the
person responsible to deliver it to the intended recipient, please contact
the sender at the email above and delete this email and any attachments and
destroy any copies thereof. Any review, retransmission, dissemination,
copying or other use of, or taking any action in reliance upon, this
information by persons or entities other than the intended recipient is
strictly prohibited.
** **
From: Sylvain Lebresne sylv...@datastax.com
Reply-To: user@cassandra.apache.org
Date: Thursday, April 11, 2013 8:48 AM
To: user@cassandra.apache.org user@cassandra.apache.org
Cc: Gabriel Ciuloaica gciuloa...@gmail.com
Subject: Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion.
It does not.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material.
If
you received this email in error and are not the intended recipient, or
the person responsible to deliver it to the intended recipient, please
contact the sender at the email above and delete this email and any
attachments and destroy any copies thereof. Any review, retransmission,
dissemination, copying or other use of, or taking any action in reliance
upon, this information by persons or entities other than the intended
recipient is strictly prohibited.
On 4/11/13 8:34 AM, Gabriel Ciuloaica gciuloa...@gmail.com wrote:
I'm not using the query builder but the PreparedStatement.
Here is the sample code: https://gist.github.com/devsprint/5363023
Gabi
On 4/11/13 3:27 PM, Brian O'Neill wrote:
Great!
Thanks Gabriel. Do you have an example? (are using QueryBuilder?)
I couldn't find the part of the
Re: multiple Datacenter values in PropertyFileSnitch
Hello, I'm not an expert but I don't think you can do what you want. The way to separate data for applications on the same cluster is to use different tables for different applications or use multiple keyspaces, a keyspace per application. The replication factor you specify for each keyspace specifies how many copies of the data are stored in each datacenter. You can't specify that data for a particular application is stored on a specific node, unless that node is in its own cluster. I think of a cassandra cluster as a shared resource where all the applications have access to all the nodes in the cluster. Thanks Jabbar Azam On 11 April 2013 14:13, Matthias Zeilinger matthias.zeilin...@bwinparty.com wrote: Hi, ** ** I would like to create big cluster for many applications. Within this cluster I would like to separate the data for each application, which can be easily done via different virtual datacenters and the correct replication strategy. What I would like to know, if I can specify for 1 node multiple values in the PropertyFileSnitch configuration, so that I can use 1 node for more applications? For example: 6 nodes: 3 for App A 3 for App B 4 for App C ** ** I want to have such a configuration: Node 1 – DC-A DC-C Node 2 – DC-B DC-C Node 3 – DC-A DC-C Node 4 – DC-B DC-C Node 5 – DC-A Node 6 – DC-B ** ** Is this possible or does anyone have another solution for this? ** ** ** ** Thx br matthias
Compaction, truncate, cqlsh problems
Hi, I use C* 1.2.3 and CQL3. I integrated cassandra into our testing environment. In order to make the tests repeatable I truncate all the tables that need to be empty before the test run via ssh session to the host cassandra runs on and by running cqlsh where I issue the truncate. It works, only sometimes it silently fails (1 in 400 runs of the truncate, actually). At the same time the truncate fails I see system ks compaction. Additionally, it seems there is quite a lot of these system ks compactions (the numbers in the filenames go up pretty fast to thousands). I googled truncate and found out there were some issues with race conditions and with slowing down if truncate is used frequently (as is my case, where truncate is run before each test in quite a big test suite). Any hints? Regards, Ondřej Černoš
Re: Blobs in CQL?
Bingo! Thanks to both of you. (the C* community rocks)
A few hours worth of work, and I've got a working REST-based photo
repository backed by C* using the CQL java driver. =)
rock on, thanks again,
-brian
On Thu, Apr 11, 2013 at 9:33 AM, Sylvain Lebresne sylv...@datastax.comwrote:
I assume I'm doing something wrong in the select. Am I incorrectly using
the ResultSet?
You're incorrectly using the returned ByteBuffer. But you should not feel
bad, that API kinda
sucks.
The short version is that .array() returns the backing array of the
ByteBuffer. But there is no
guarantee that you'll have a one-to-one correspondence between the valid
content of the
ByteBuffer and the backing array, the backing array can be bigger in
particular (long story short,
this allows multiple ByteBuffer to share the same backing array, which can
avoid doing copies).
I also note that there is no guarantee that .array() will work unless
you've called .hasArray().
Anyway, what you could do is:
ByteBuffer bb = resultSet.one().getBytes(data);
byte[] data = new byte[bb.remaining()];
bb.get(data);
Alternatively, you can use the result of .array(), but you should only
consider the bb.remaining()
bytes starting at bb.arrayOffset() + bb.position() (where bb is the
returned ByteBuffer).
--
Sylvain
-brian
On Thu, Apr 11, 2013 at 9:09 AM, Brian O'Neill b...@alumni.brown.eduwrote:
Yep, it worked like a charm. (PreparedStatement avoided the hex
conversion)
But now, I'm seeing a few extra bytes come back in the select….
(I'll keep digging, but maybe you have some insight?)
I see this:
ERROR [2013-04-11 13:05:03,461] com.skookle.dao.RepositoryDao:
repository.add() byte.length()=[259804]
ERROR [2013-04-11 13:08:08,487] com.skookle.dao.RepositoryDao:
repository.get() [foo.jpeg] byte.length()=[259861]
(Notice the length's don't match up)
Using this code:
public void addContent(String key, byte[] data)
throws NoHostAvailableException {
LOG.error(repository.add() byte.length()=[ + data.length + ]
);
String statement = INSERT INTO + KEYSPACE + . + TABLE + (key,
data) VALUES (?, ?);
PreparedStatement ps = session.prepare(statement);
BoundStatement bs = ps.bind(key, ByteBuffer.wrap(data));
session.execute(bs);
}
public byte[] getContent(String key) throwsNoHostAvailableException {
Query select = select(data).from(KEYSPACE, TABLE).where(eq(
key, key));
ResultSet resultSet = session.execute(select);
byte[] data = resultSet.one().getBytes(data).array();
LOG.error(repository.get() [ + key + ] byte.length()=[ +
data.length + ]);
return data;
}
---
Brian O'Neill
Lead Architect, Software Development
*Health Market Science*
*The Science of Better Results*
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
This information transmitted in this email message is for the intended
recipient only and may contain confidential and/or privileged material. If
you received this email in error and are not the intended recipient, or the
person responsible to deliver it to the intended recipient, please contact
the sender at the email above and delete this email and any attachments and
destroy any copies thereof. Any review, retransmission, dissemination,
copying or other use of, or taking any action in reliance upon, this
information by persons or entities other than the intended recipient is
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** **
From: Sylvain Lebresne sylv...@datastax.com
Reply-To: user@cassandra.apache.org
Date: Thursday, April 11, 2013 8:48 AM
To: user@cassandra.apache.org user@cassandra.apache.org
Cc: Gabriel Ciuloaica gciuloa...@gmail.com
Subject: Re: Blobs in CQL?
Hopefully, the prepared statement doesn't do the conversion.
It does not.
(I'm not sure if it is a limitation of the CQL protocol itself)
thanks again,
-brian
---
Brian O'Neill
Lead Architect, Software Development
Health Market Science
The Science of Better Results
2700 Horizon Drive • King of Prussia, PA • 19406
M: 215.588.6024 • @boneill42 http://www.twitter.com/boneill42 •
healthmarketscience.com
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On 4/11/13 8:34 AM, Gabriel Ciuloaica
Re: CorruptedBlockException
Aaron,
It seems that we are in the same situation as Nury, we are storing a lot of
files of ~5MB in a CF.
This happens in a test cluster, with one node using cassandra 1.1.5, we
have commitlog in a different partition than the data directory. Normally
our tests use nearly 13 GB in data, but when the exception on compaction
appears our disk space ramp up to:
# df -h
FilesystemSize Used Avail Use% Mounted on
/dev/sda1 440G 330G 89G 79% /
tmpfs 7.9G 0 7.9G 0% /lib/init/rw
udev 7.9G 160K 7.9G 1% /dev
tmpfs 7.9G 0 7.9G 0% /dev/shm
/dev/sdb1 459G 257G 179G 59% /cassandra
# cd /cassandra/data/Repository/
# ls Files/*tmp* | wc -l
1671
# du -ch Files | tail -1
257Gtotal
# du -ch Files/*tmp* | tail -1
34G total
We are using cassandra 1.1.5 with one node, our schema for that keyspace is:
[default@unknown] use Repository;
Authenticated to keyspace: Repository
[default@Repository] show schema;
create keyspace Repository
with placement_strategy = 'NetworkTopologyStrategy'
and strategy_options = {datacenter1 : 1}
and durable_writes = true;
use Repository;
create column family Files
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'BytesType'
and key_validation_class = 'BytesType'
and read_repair_chance = 0.1
and dclocal_read_repair_chance = 0.0
and gc_grace = 864000
and min_compaction_threshold = 4
and max_compaction_threshold = 32
and replicate_on_write = true
and compaction_strategy =
'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'
and caching = 'KEYS_ONLY'
and compaction_strategy_options = {'sstable_size_in_mb' : '120'}
and compression_options = {'sstable_compression' :
'org.apache.cassandra.io.compress.SnappyCompressor'};
In our logs:
ERROR [CompactionExecutor:1831] 2013-04-11 09:12:41,725
AbstractCassandraDaemon.java (line 135) Exception in thread
Thread[CompactionExecutor:1831,1,main]
java.io.IOError: org.apache.cassandra.io.compress.CorruptedBlockException:
(/cassandra/data/Repository/Files/Repository-Files-he-4533-Data.db):
corruption detected, chunk at 43325354 of length 65545.
at
org.apache.cassandra.db.compaction.PrecompactedRow.merge(PrecompactedRow.java:116)
at
org.apache.cassandra.db.compaction.PrecompactedRow.init(PrecompactedRow.java:99)
at
org.apache.cassandra.db.compaction.CompactionController.getCompactedRow(CompactionController.java:176)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:83)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:68)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.consume(MergeIterator.java:118)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.computeNext(MergeIterator.java:101)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at
com.google.common.collect.Iterators$7.computeNext(Iterators.java:614)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at
org.apache.cassandra.db.compaction.CompactionTask.execute(CompactionTask.java:173)
at
org.apache.cassandra.db.compaction.LeveledCompactionTask.execute(LeveledCompactionTask.java:50)
at
org.apache.cassandra.db.compaction.CompactionManager$1.runMayThrow(CompactionManager.java:154)
at
org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:30)
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at
java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)
On Thu, Jul 5, 2012 at 7:42 PM, aaron morton aa...@thelastpickle.comwrote:
But I don't understand, how was all the available space taken away.
Take a look on disk at /var/lib/cassandra/data/your_keyspace and
/var/lib/cassandra/commitlog to see what is taking up a lot of space.
Cassandra stores the column names as well as the values, so that can take
up some space.
it says that while compaction a CorruptedBlockException has occured.
Are you able to reproduce this error ?
Thanks
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 6/07/2012, at 12:04 AM, Nury Redjepow wrote:
Hello to all,
I have cassandra instance I'm trying to use to store millions of file
with
RE: CorruptedBlockException
I have formulated the following theory regarding C* 1.2.2 which may be
relevant: Whenever there is a disk error during compaction of an SS table
(e.g., bad block, out of disk space), that SStable's files stick around forever
after, and do not subsequently get deleted by normal compaction (minor or
major), long after all its records have been deleted. This causes disk usage to
rise dramatically. The only way to make the SStable files disappear is to run
nodetool cleanup (which takes hours to run).
Just a theory so far
From: Alexis Rodríguez [mailto:arodrig...@inconcertcc.com]
Sent: Thursday, April 11, 2013 5:31 PM
To: user@cassandra.apache.org
Subject: Re: CorruptedBlockException
Aaron,
It seems that we are in the same situation as Nury, we are storing a lot of
files of ~5MB in a CF.
This happens in a test cluster, with one node using cassandra 1.1.5, we have
commitlog in a different partition than the data directory. Normally our tests
use nearly 13 GB in data, but when the exception on compaction appears our disk
space ramp up to:
# df -h
FilesystemSize Used Avail Use% Mounted on
/dev/sda1 440G 330G 89G 79% /
tmpfs 7.9G 0 7.9G 0% /lib/init/rw
udev 7.9G 160K 7.9G 1% /dev
tmpfs 7.9G 0 7.9G 0% /dev/shm
/dev/sdb1 459G 257G 179G 59% /cassandra
# cd /cassandra/data/Repository/
# ls Files/*tmp* | wc -l
1671
# du -ch Files | tail -1
257Gtotal
# du -ch Files/*tmp* | tail -1
34G total
We are using cassandra 1.1.5 with one node, our schema for that keyspace is:
[default@unknown] use Repository;
Authenticated to keyspace: Repository
[default@Repository] show schema;
create keyspace Repository
with placement_strategy = 'NetworkTopologyStrategy'
and strategy_options = {datacenter1 : 1}
and durable_writes = true;
use Repository;
create column family Files
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'BytesType'
and key_validation_class = 'BytesType'
and read_repair_chance = 0.1
and dclocal_read_repair_chance = 0.0
and gc_grace = 864000
and min_compaction_threshold = 4
and max_compaction_threshold = 32
and replicate_on_write = true
and compaction_strategy =
'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'
and caching = 'KEYS_ONLY'
and compaction_strategy_options = {'sstable_size_in_mb' : '120'}
and compression_options = {'sstable_compression' :
'org.apache.cassandra.io.compress.SnappyCompressor'};
In our logs:
ERROR [CompactionExecutor:1831] 2013-04-11 09:12:41,725
AbstractCassandraDaemon.java (line 135) Exception in thread
Thread[CompactionExecutor:1831,1,main]
java.io.IOError: org.apache.cassandra.io.compress.CorruptedBlockException:
(/cassandra/data/Repository/Files/Repository-Files-he-4533-Data.db): corruption
detected, chunk at 43325354 of length 65545.
at
org.apache.cassandra.db.compaction.PrecompactedRow.merge(PrecompactedRow.java:116)
at
org.apache.cassandra.db.compaction.PrecompactedRow.init(PrecompactedRow.java:99)
at
org.apache.cassandra.db.compaction.CompactionController.getCompactedRow(CompactionController.java:176)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:83)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:68)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.consume(MergeIterator.java:118)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.computeNext(MergeIterator.java:101)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at com.google.common.collect.Iterators$7.computeNext(Iterators.java:614)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at
org.apache.cassandra.db.compaction.CompactionTask.execute(CompactionTask.java:173)
at
org.apache.cassandra.db.compaction.LeveledCompactionTask.execute(LeveledCompactionTask.java:50)
at
org.apache.cassandra.db.compaction.CompactionManager$1.runMayThrow(CompactionManager.java:154)
at
org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:30)
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)
On Thu, Jul 5,
Re: Compaction, truncate, cqlsh problems
If you do not have JNA truncate has to fork an 'ln -s'' command for the snapshots. I think that makes it un-predicatable. Truncate has its own timeout value now (separate from the other timeouts). If possible I think it is better to make each test use it's own CF and avoid truncate entirely. On Thu, Apr 11, 2013 at 9:48 AM, Ondřej Černoš cern...@gmail.com wrote: Hi, I use C* 1.2.3 and CQL3. I integrated cassandra into our testing environment. In order to make the tests repeatable I truncate all the tables that need to be empty before the test run via ssh session to the host cassandra runs on and by running cqlsh where I issue the truncate. It works, only sometimes it silently fails (1 in 400 runs of the truncate, actually). At the same time the truncate fails I see system ks compaction. Additionally, it seems there is quite a lot of these system ks compactions (the numbers in the filenames go up pretty fast to thousands). I googled truncate and found out there were some issues with race conditions and with slowing down if truncate is used frequently (as is my case, where truncate is run before each test in quite a big test suite). Any hints? Regards, Ondřej Černoš
Re: Column index vs Row index vs Denormalizing
Thanks for the feedback! We will be going forward by implementing and deploying the proposed model, and test it out. Cheers, Coen On Thu, Apr 11, 2013 at 12:21 PM, aaron morton aa...@thelastpickle.comwrote: Retrieving the latest 1000 tweets (of a given day) is trivial by requesting the streamTweets columnFamily. If you normally want to get the most recent items use a reverse comparator on the column name see http://thelastpickle.com/2011/10/03/Reverse-Comparators/ Getting the latest tweets for a given hashtag would mean you have to get the TimeUUIDs from the streamHashTagTweets first, and then do a second get call on the streamTweets with the former TimeUUIDs as the list of columns we like to retrieve (column index). You choices here depend on what sort of queries are the most frequent and how much disk space you have. You current model makes sense if the stream by day is the most frequent query, and you want to conserve disk space. If disk space is not an issue you can denormalise further and store the tweet JSON. If you have potentially many streamHashTagTweets rows where a single tweet is replicated it may make sense to stick with the current design to reduce disk use. (we want to get up to 1000 tweets). If you want to get 1000 anything from cassandra please break the multiget up into multiple calls. Each row request becomes a task in the thread pools on RF nodes. If you have a small ish cluster one client asking for 1000 rows will temporarily block other clients and hurt request throughput. Referencing key values requires another columnFamily for tweets (key: tweetId, columns: 1 column with data). This will be a more efficient (aka faster) read than reading from the a wide row. Next to that we will request tweets by these secondary indexes quite infrequently, while the tweets by timestamp will be requested heavily. If the hot path is the streamTweets calls demoralise into that, and normalise the tweet storage into it's own CF and reference them from the streamHashTagTweets. Have a canonical store of the events / tweets / entities addressable by their business key can give you more flexibility. Given we are estimating to store many TBs of tweets, we would prefer setting up machines with spinning disks (2TB per node) to save costs. If you have spinning disks and 1G networking the rule of thumb is 300GB to 500GB per node. See previous discussions about size per node. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 10/04/2013, at 2:00 AM, Coen Stevens beatle...@gmail.com wrote: Hi all, We are working on a data model for storing tweets for multiple streams (where a stream is defined by a number of keyword filters on the full twitter firehose), and retrieving the tweets by timestamp and hashtag. My question is whether the following data model would a good way for doing that, where I'm creating a column name index for the hashtags. ColumnFamily: streamTweets key: streamID + dayTimestamp (creating daily buckets for each stream) columns = name: TimeUUID, value: tweet json (storing all the tweets for this stream in a wide row with a TimeUUID) ColumnFamily: streamHashTagTweets key: streamID + dayTimestamp + hashTag (e.g. 123_2013-04-02_cassandra) columns = name: TimeUUID (referencing the TimeUUID value in the streamTweets ColumnFamily), value: tweetID Retrieving the latest 1000 tweets (of a given day) is trivial by requesting the streamTweets columnFamily. Getting the latest tweets for a given hashtag would mean you have to get the TimeUUIDs from the streamHashTagTweets first, and then do a second get call on the streamTweets with the former TimeUUIDs as the list of columns we like to retrieve (column index). Is referencing column names (TimeUUIDs) a smart thing to do when we have wide rows spanning millions of columns? It seems easier (one reference call) to do this, then it is to reference key values and running a multi-get to get all the rows (we want to get up to 1000 tweets). Referencing key values requires another columnFamily for tweets (key: tweetId, columns: 1 column with data). Of course we could instead denormalize the data and store the tweet also in the streamHashTagTweet columns, but we want to do the same thing for other indexes as well (topics, twitter usernames, links, etc), so it quickly adds up in required storage space. Next to that we will request tweets by these secondary indexes quite infrequently, while the tweets by timestamp will be requested heavily. Given we are estimating to store many TBs of tweets, we would prefer setting up machines with spinning disks (2TB per node) to save costs. We would love to hear your feedback. Cheers, Coen
Re: Compaction, truncate, cqlsh problems
Hi, I have JNA (cassandra only complains about obsolete version - Obsolete version of JNA present; unable to read errno. Upgrade to JNA 3.2.7 or later - I have stock centos version 3.2.4). Usage of separate CFs for each test run is difficult to set up. Can you please elaborate on the specials of truncate? regards, Ondřej Černoš On Thu, Apr 11, 2013 at 5:04 PM, Edward Capriolo edlinuxg...@gmail.comwrote: If you do not have JNA truncate has to fork an 'ln -s'' command for the snapshots. I think that makes it un-predicatable. Truncate has its own timeout value now (separate from the other timeouts). If possible I think it is better to make each test use it's own CF and avoid truncate entirely. On Thu, Apr 11, 2013 at 9:48 AM, Ondřej Černoš cern...@gmail.com wrote: Hi, I use C* 1.2.3 and CQL3. I integrated cassandra into our testing environment. In order to make the tests repeatable I truncate all the tables that need to be empty before the test run via ssh session to the host cassandra runs on and by running cqlsh where I issue the truncate. It works, only sometimes it silently fails (1 in 400 runs of the truncate, actually). At the same time the truncate fails I see system ks compaction. Additionally, it seems there is quite a lot of these system ks compactions (the numbers in the filenames go up pretty fast to thousands). I googled truncate and found out there were some issues with race conditions and with slowing down if truncate is used frequently (as is my case, where truncate is run before each test in quite a big test suite). Any hints? Regards, Ondřej Černoš
is the select result grouped by the value of the partition key?
Hello,
Let us consider that we have a table t created as follows:
create table t(k1 vachar, k2 varchar, value varchar, primary key (k1, k2));
Its contents is
a m x
a n y
z 0 9
z 1 8
and I perform a
select * from p where k1 in ('a', 'z');
Is it guaranteed that the rows are grouped by the value of the partition
key? That is, is it guaranteed that I'll get
a m x
a n y
z 0 9
z 1 8
or
a n y
a m x
z 1 8
z 0 9
or even
z 0 9
z 1 8
a n y
a m x
but NEVER
a m x
z 0 9
a n y
z 1 8
Thank you,
Sorin
[RELEASE] Apache Cassandra 1.2.4 released
The Cassandra team is pleased to announce the release of Apache Cassandra version 1.2.4. Cassandra is a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model. You can read more here: http://cassandra.apache.org/ Downloads of source and binary distributions are listed in our download section: http://cassandra.apache.org/download/ This version is a maintenance/bug fix release[1] on the 1.2 series. As always, please pay attention to the release notes[2] and Let us know[3] if you were to encounter any problem. Enjoy! [1]: http://goo.gl/t7x9f (CHANGES.txt) [2]: http://goo.gl/6IEbR (NEWS.txt) [3]: https://issues.apache.org/jira/browse/CASSANDRA
Re: Two Cluster each with 12 nodes- Cassandra database
Folks, Any thoughts on this? I am still in the learning process. So any guidance will be of great help. *Raihan Jamal* On Wed, Apr 10, 2013 at 10:39 PM, Raihan Jamal jamalrai...@gmail.comwrote: I have started working on a project in which I am using `Cassandra database`. Our production DBA's have setup `two cluster` and each cluster will have `12 nodes`. I will be using `Pelops client` to read the data from Cassandra database. Now I am thinking what's the best way to create `Cluster` using `Pelops client` like how many nodes I should add while creating cluster? My understanding was to create the cluster with all the `24 nodes` as I will be having two cluster each with 12 nodes? This is the right approach? *If not, then how we decide what nodes (from each cluster) I should add while creating the cluster using Pelops client? * String[] nodes = cfg.getStringArray(cassandra.servers); int port = cfg.getInt(cassandra.port); boolean dynamicND = true; // dynamic node discovery Config casconf = new Config(port, true, 0); Cluster cluster = new Cluster(nodes, casconf, dynamicND); Pelops.addPool(Const.CASSANDRA_POOL, cluster, Const.CASSANDRA_KS); Can anyone help me out with this? Any help will be appreciated. **
Re: multiple Datacenter values in PropertyFileSnitch
A node can only exist in one DC and one rack. Use different keyspaces as suggested. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 1:47 AM, Jabbar Azam aja...@gmail.com wrote: Hello, I'm not an expert but I don't think you can do what you want. The way to separate data for applications on the same cluster is to use different tables for different applications or use multiple keyspaces, a keyspace per application. The replication factor you specify for each keyspace specifies how many copies of the data are stored in each datacenter. You can't specify that data for a particular application is stored on a specific node, unless that node is in its own cluster. I think of a cassandra cluster as a shared resource where all the applications have access to all the nodes in the cluster. Thanks Jabbar Azam On 11 April 2013 14:13, Matthias Zeilinger matthias.zeilin...@bwinparty.com wrote: Hi, I would like to create big cluster for many applications. Within this cluster I would like to separate the data for each application, which can be easily done via different virtual datacenters and the correct replication strategy. What I would like to know, if I can specify for 1 node multiple values in the PropertyFileSnitch configuration, so that I can use 1 node for more applications? For example: 6 nodes: 3 for App A 3 for App B 4 for App C I want to have such a configuration: Node 1 – DC-A DC-C Node 2 – DC-B DC-C Node 3 – DC-A DC-C Node 4 – DC-B DC-C Node 5 – DC-A Node 6 – DC-B Is this possible or does anyone have another solution for this? Thx br matthias
Re: Two Cluster each with 12 nodes- Cassandra database
Hello, I don't know what pelops is. I'm not sure why you want two clusters. I would have two clusters if I want to have data stored on totally separate servers for perhaps security reasons. If you are going to have the servers in one location then you might as well have one cluster. You'll have the maximum aggregate io of all the servers. If you're thinking of doing analytics as well then you can create two virtual datacentres. One for realtime inserts and reads and the second for analytics. You could have have and 16 /8 server split. Obviously you'll have to work out what the optimum split is for your workload. Not sure if I've answered your question... On 11 Apr 2013 18:51, Raihan Jamal jamalrai...@gmail.com wrote: Folks, Any thoughts on this? I am still in the learning process. So any guidance will be of great help. *Raihan Jamal* On Wed, Apr 10, 2013 at 10:39 PM, Raihan Jamal jamalrai...@gmail.comwrote: I have started working on a project in which I am using `Cassandra database`. Our production DBA's have setup `two cluster` and each cluster will have `12 nodes`. I will be using `Pelops client` to read the data from Cassandra database. Now I am thinking what's the best way to create `Cluster` using `Pelops client` like how many nodes I should add while creating cluster? My understanding was to create the cluster with all the `24 nodes` as I will be having two cluster each with 12 nodes? This is the right approach? *If not, then how we decide what nodes (from each cluster) I should add while creating the cluster using Pelops client? * String[] nodes = cfg.getStringArray(cassandra.servers); int port = cfg.getInt(cassandra.port); boolean dynamicND = true; // dynamic node discovery Config casconf = new Config(port, true, 0); Cluster cluster = new Cluster(nodes, casconf, dynamicND); Pelops.addPool(Const.CASSANDRA_POOL, cluster, Const.CASSANDRA_KS); Can anyone help me out with this? Any help will be appreciated. **
Re: describe keyspace or column family query not working
tables created without COMPACT STORAGE are still visible in cassandra-cli. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 11/04/2013, at 5:40 AM, Tyler Hobbs ty...@datastax.com wrote: On Wed, Apr 10, 2013 at 11:09 AM, Vivek Mishra mishra.v...@gmail.com wrote: Ok. A column family and keyspace created via cqlsh using cql3 is visible via cassandra-cli or thrift API? The column family will only be visible via cassandra-cli and the Thrift API if it was created WITH COMPACT STORAGE: http://www.datastax.com/docs/1.2/cql_cli/cql/CREATE_TABLE#using-compact-storage -- Tyler Hobbs DataStax
Re: (info) Abort the seek op in SSTableIdentityIterator class.
When created by the SSTableScanner the dataStart passed in is the existing file position so it may not be necessary. But it may be sane to do it and the seek() call may not result in disk reads. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 1:48 AM, dong.yajun dongt...@gmail.com wrote: Hello, I read the source code of SSTableIdentityIterator with v-1.0.9, and I thought the following code is not necessary, did I miss anything? RandomAccessReader file = (RandomAccessReader) input; file.seek(this.dataStart); here, the value of dataStart is assigned in SSTableScanner: long dataStart = file.getFilePointer(); any suggestion abort this issue? thanks. Best, -- Rick Dong
running cassandra on 8 GB servers
For one project I will need to run cassandra on following dedicated servers: Single CPU XEON 4 cores no hyper-threading, 8 GB RAM, 12 TB locally attached HDD's in some kind of RAID, visible as single HDD. I can do cluster of 20-30 such servers, may be even more. The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. Currently I am testing with one of such servers, except HDD is 300 GB. Every 15-20 hours, I get out of heap memory, e.g. something like: ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,943 Gossiper.java (line 1077) Announcing shutdown INFO [StorageServiceShutdownHook] 2013-04-11 11:26:08,613 MessagingService.java (line 682) Waiting for messaging service to quiesce INFO [ACCEPT-/208.94.232.37] 2013-04-11 11:26:08,655 MessagingService.java (line 888) MessagingService shutting down server thread. ERROR [Thrift:721] 2013-04-11 11:26:37,709 CustomTThreadPoolServer.java (line 217) Error occurred during processing of message. java.util.concurrent.RejectedExecutionException: ThreadPoolExecutor has shut down Anyone have some advices about better utilization of such servers? Nick.
Re: Compaction, truncate, cqlsh problems
Can you please elaborate on the specials of truncate? I think ed was talking about this config setting in 1.2 https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L484 It works, only sometimes it silently fails (1 in 400 runs of the truncate, actually). The data is left in place ? Are you making the calls very quickly? If you add a pause does it help ? At the same time the truncate fails I see system ks compaction. Additionally, it seems there is quite a lot of these system ks compactions (the numbers in the filenames go up pretty fast to thousands). In 1.2 truncate updates a system table, which always flush after updates. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 3:12 AM, Ondřej Černoš cern...@gmail.com wrote: Hi, I have JNA (cassandra only complains about obsolete version - Obsolete version of JNA present; unable to read errno. Upgrade to JNA 3.2.7 or later - I have stock centos version 3.2.4). Usage of separate CFs for each test run is difficult to set up. Can you please elaborate on the specials of truncate? regards, Ondřej Černoš On Thu, Apr 11, 2013 at 5:04 PM, Edward Capriolo edlinuxg...@gmail.com wrote: If you do not have JNA truncate has to fork an 'ln -s'' command for the snapshots. I think that makes it un-predicatable. Truncate has its own timeout value now (separate from the other timeouts). If possible I think it is better to make each test use it's own CF and avoid truncate entirely. On Thu, Apr 11, 2013 at 9:48 AM, Ondřej Černoš cern...@gmail.com wrote: Hi, I use C* 1.2.3 and CQL3. I integrated cassandra into our testing environment. In order to make the tests repeatable I truncate all the tables that need to be empty before the test run via ssh session to the host cassandra runs on and by running cqlsh where I issue the truncate. It works, only sometimes it silently fails (1 in 400 runs of the truncate, actually). At the same time the truncate fails I see system ks compaction. Additionally, it seems there is quite a lot of these system ks compactions (the numbers in the filenames go up pretty fast to thousands). I googled truncate and found out there were some issues with race conditions and with slowing down if truncate is used frequently (as is my case, where truncate is run before each test in quite a big test suite). Any hints? Regards, Ondřej Černoš
Re: is the select result grouped by the value of the partition key?
Is it guaranteed that the rows are grouped by the value of the partition key?
That is, is it guaranteed that I'll get
Your primary key (k1, k2) is considered in type parts (partition_key ,
grouping_columns). In your case the primary_key is key and the grouping column
in k2. Columns are ordered by the grouping columns, k2.
See http://thelastpickle.com/2013/01/11/primary-keys-in-cql/
Cheers
-
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 12/04/2013, at 3:19 AM, Sorin Manolache sor...@gmail.com wrote:
Hello,
Let us consider that we have a table t created as follows:
create table t(k1 vachar, k2 varchar, value varchar, primary key (k1, k2));
Its contents is
a m x
a n y
z 0 9
z 1 8
and I perform a
select * from p where k1 in ('a', 'z');
Is it guaranteed that the rows are grouped by the value of the partition key?
That is, is it guaranteed that I'll get
a m x
a n y
z 0 9
z 1 8
or
a n y
a m x
z 1 8
z 0 9
or even
z 0 9
z 1 8
a n y
a m x
but NEVER
a m x
z 0 9
a n y
z 1 8
Thank you,
Sorin
Re: CorruptedBlockException
Whenever there is a disk error during compaction of an SS table (e.g., bad block, out of disk space), that SStable’s files stick around forever after Fixed in 1.1.1 https://issues.apache.org/jira/browse/CASSANDRA-2261 We are using 1.1.5, besides that I have tried to run cleanup, with no success :( That is not what cleanup is used for. It is used to delete data that a node is no longer responsible for. If you have a log of -tmp- files created through a problem like this a restart will delete them. If you have an error reading data of disk use nodetool scrub. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 3:35 AM, Alexis Rodríguez arodrig...@inconcertcc.com wrote: Moshe, We are using 1.1.5, besides that I have tried to run cleanup, with no success :( # nodetool -p 8080 cleanup Error occured during cleanup java.util.concurrent.ExecutionException: java.io.IOError: org.apache.cassandra.io.compress.CorruptedBlockException: (/cass andra/data/Repository/Files/Repository-Files-he-4533-Data.db): corruption detected, chunk at 43325354 of length 65545. at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:252) at java.util.concurrent.FutureTask.get(FutureTask.java:111) at org.apache.cassandra.db.compaction.CompactionManager.performAllSSTableOperation(CompactionManager.java:216) at org.apache.cassandra.db.compaction.CompactionManager.performCleanup(CompactionManager.java:252) at org.apache.cassandra.db.ColumnFamilyStore.forceCleanup(ColumnFamilyStore.java:970) at org.apache.cassandra.service.StorageService.forceTableCleanup(StorageService.java:1772) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:111) at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:45) at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:226) at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138) at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:251) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:857) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:795) at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1450) at javax.management.remote.rmi.RMIConnectionImpl.access$200(RMIConnectionImpl.java:90) at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1285) at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1383) at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:807) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) On Thu, Apr 11, 2013 at 11:45 AM, moshe.kr...@barclays.com wrote: I have formulated the following theory regarding C* 1.2.2 which may be relevant: Whenever there is a disk error during compaction of an SS table (e.g., bad block, out of disk space), that SStable’s files stick around forever after, and do not subsequently get deleted by normal compaction (minor or major), long after all its records have been deleted. This causes disk usage to rise dramatically. The only way to make the SStable files disappear is to run “nodetool cleanup” (which takes hours to run). Just a theory so far…. From: Alexis Rodríguez [mailto:arodrig...@inconcertcc.com] Sent: Thursday, April 11, 2013 5:31 PM To: user@cassandra.apache.org Subject: Re: CorruptedBlockException Aaron, It seems that we are in the same situation as Nury, we are storing a lot of files of ~5MB in a CF. This happens in a test cluster, with one node using cassandra 1.1.5, we have commitlog in a different partition than the data directory. Normally our tests use nearly 13 GB in data, but when the exception on compaction appears our disk space ramp up to: # df -h FilesystemSize Used Avail Use% Mounted on /dev/sda1 440G 330G 89G 79% / tmpfs 7.9G 0 7.9G 0% /lib/init/rw udev 7.9G 160K 7.9G 1% /dev tmpfs 7.9G 0 7.9G 0% /dev/shm /dev/sdb1 459G 257G 179G 59% /cassandra # cd
Re: Two Cluster each with 12 nodes- Cassandra database
I will be using `Pelops client` If you are starting out using Java I *strongly* suggest using this client https://github.com/Netflix/astyanax/ see the documentation here https://github.com/Netflix/astyanax/wiki My understanding was to create the cluster with all the `24 nodes` as I will be having two cluster each with 12 nodes? This is the right approach? As discussed, you can have two separate clusters but you probably want to have one cluster with two data centres, each with 12 nodes. See http://www.datastax.com/docs/1.2/initialize/cluster_init Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 6:45 AM, Jabbar Azam aja...@gmail.com wrote: Hello, I don't know what pelops is. I'm not sure why you want two clusters. I would have two clusters if I want to have data stored on totally separate servers for perhaps security reasons. If you are going to have the servers in one location then you might as well have one cluster. You'll have the maximum aggregate io of all the servers. If you're thinking of doing analytics as well then you can create two virtual datacentres. One for realtime inserts and reads and the second for analytics. You could have have and 16 /8 server split. Obviously you'll have to work out what the optimum split is for your workload. Not sure if I've answered your question... On 11 Apr 2013 18:51, Raihan Jamal jamalrai...@gmail.com wrote: Folks, Any thoughts on this? I am still in the learning process. So any guidance will be of great help. Raihan Jamal On Wed, Apr 10, 2013 at 10:39 PM, Raihan Jamal jamalrai...@gmail.com wrote: I have started working on a project in which I am using `Cassandra database`. Our production DBA's have setup `two cluster` and each cluster will have `12 nodes`. I will be using `Pelops client` to read the data from Cassandra database. Now I am thinking what's the best way to create `Cluster` using `Pelops client` like how many nodes I should add while creating cluster? My understanding was to create the cluster with all the `24 nodes` as I will be having two cluster each with 12 nodes? This is the right approach? If not, then how we decide what nodes (from each cluster) I should add while creating the cluster using Pelops client? String[] nodes = cfg.getStringArray(cassandra.servers); int port = cfg.getInt(cassandra.port); boolean dynamicND = true; // dynamic node discovery Config casconf = new Config(port, true, 0); Cluster cluster = new Cluster(nodes, casconf, dynamicND); Pelops.addPool(Const.CASSANDRA_POOL, cluster, Const.CASSANDRA_KS); Can anyone help me out with this? Any help will be appreciated.
Re: running cassandra on 8 GB servers
The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. You will have a very unhappy time. The general rule of thumb / guideline for a HDD based system with 1G networking is 300GB to 500Gb per node. See previous discussions on this topic for reasons. ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients What was the error ? What version are you using? If you have changed any defaults for memory in cassandra-env.sh or cassandra.yaml revert them. Generally C* will do the right thing and not OOM, unless you are trying to store a lot of data on a node that does not have enough memory. See this thread for background http://www.mail-archive.com/user@cassandra.apache.org/msg25762.html Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 7:35 AM, Nikolay Mihaylov n...@nmmm.nu wrote: For one project I will need to run cassandra on following dedicated servers: Single CPU XEON 4 cores no hyper-threading, 8 GB RAM, 12 TB locally attached HDD's in some kind of RAID, visible as single HDD. I can do cluster of 20-30 such servers, may be even more. The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. Currently I am testing with one of such servers, except HDD is 300 GB. Every 15-20 hours, I get out of heap memory, e.g. something like: ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,943 Gossiper.java (line 1077) Announcing shutdown INFO [StorageServiceShutdownHook] 2013-04-11 11:26:08,613 MessagingService.java (line 682) Waiting for messaging service to quiesce INFO [ACCEPT-/208.94.232.37] 2013-04-11 11:26:08,655 MessagingService.java (line 888) MessagingService shutting down server thread. ERROR [Thrift:721] 2013-04-11 11:26:37,709 CustomTThreadPoolServer.java (line 217) Error occurred during processing of message. java.util.concurrent.RejectedExecutionException: ThreadPoolExecutor has shut down Anyone have some advices about better utilization of such servers? Nick.
Re: running cassandra on 8 GB servers
With that much data per node you have to raise the IndexInterval and adjust the bloom filter settings. Although the bloom filters are off heap now having that much data can but a strain on physical memory. On Thu, Apr 11, 2013 at 4:26 PM, aaron morton aa...@thelastpickle.comwrote: The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. You will have a very unhappy time. The general rule of thumb / guideline for a HDD based system with 1G networking is 300GB to 500Gb per node. See previous discussions on this topic for reasons. ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients What was the error ? What version are you using? If you have changed any defaults for memory in cassandra-env.sh or cassandra.yaml revert them. Generally C* will do the right thing and not OOM, unless you are trying to store a lot of data on a node that does not have enough memory. See this thread for background http://www.mail-archive.com/user@cassandra.apache.org/msg25762.html Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 7:35 AM, Nikolay Mihaylov n...@nmmm.nu wrote: For one project I will need to run cassandra on following dedicated servers: Single CPU XEON 4 cores no hyper-threading, 8 GB RAM, 12 TB locally attached HDD's in some kind of RAID, visible as single HDD. I can do cluster of 20-30 such servers, may be even more. The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. Currently I am testing with one of such servers, except HDD is 300 GB. Every 15-20 hours, I get out of heap memory, e.g. something like: ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,943 Gossiper.java (line 1077) Announcing shutdown INFO [StorageServiceShutdownHook] 2013-04-11 11:26:08,613 MessagingService.java (line 682) Waiting for messaging service to quiesce INFO [ACCEPT-/208.94.232.37] 2013-04-11 11:26:08,655 MessagingService.java (line 888) MessagingService shutting down server thread. ERROR [Thrift:721] 2013-04-11 11:26:37,709 CustomTThreadPoolServer.java (line 217) Error occurred during processing of message. java.util.concurrent.RejectedExecutionException: ThreadPoolExecutor has shut down Anyone have some advices about better utilization of such servers? Nick.
Re: running cassandra on 8 GB servers
I am using 1.2.3, used default heap - 2 GB without JNA installed, then modified heap to 4 GB / 400 MB young generation. + JNA installed. bloom filter on the CF's is lowered (more false positives, less disk space). WARN [ScheduledTasks:1] 2013-04-11 11:09:41,899 GCInspector.java (line 142) Heap is 0.9885574036095974 full. You may need to reduce memtable and/or cache sizes. Cassandra will now flush up to the two largest memtables to free up memory. Adjust flush_largest_memtables_at threshold in cassandra.yaml if you don't want Cassandra to do this automatically WARN [ScheduledTasks:1] 2013-04-11 11:09:41,906 StorageService.java (line 3541) Flushing CFS(Keyspace='CRAWLER', ColumnFamily='counters') to relieve memory pressure INFO [ScheduledTasks:1] 2013-04-11 11:09:41,949 ColumnFamilyStore.java (line 637) Enqueuing flush of Memtable-counters@862481781(711504/6211531 serialized/live bytes, 11810 ops) ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] java.lang.OutOfMemoryError: *Java heap space* On Thu, Apr 11, 2013 at 11:26 PM, aaron morton aa...@thelastpickle.comwrote: The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. You will have a very unhappy time. The general rule of thumb / guideline for a HDD based system with 1G networking is 300GB to 500Gb per node. See previous discussions on this topic for reasons. ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients What was the error ? What version are you using? If you have changed any defaults for memory in cassandra-env.sh or cassandra.yaml revert them. Generally C* will do the right thing and not OOM, unless you are trying to store a lot of data on a node that does not have enough memory. See this thread for background http://www.mail-archive.com/user@cassandra.apache.org/msg25762.html Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 7:35 AM, Nikolay Mihaylov n...@nmmm.nu wrote: For one project I will need to run cassandra on following dedicated servers: Single CPU XEON 4 cores no hyper-threading, 8 GB RAM, 12 TB locally attached HDD's in some kind of RAID, visible as single HDD. I can do cluster of 20-30 such servers, may be even more. The data will be huge, I am estimating 4-6 TB per server. I know this is best, but those are my resources. Currently I am testing with one of such servers, except HDD is 300 GB. Every 15-20 hours, I get out of heap memory, e.g. something like: ERROR [Thrift:641] 2013-04-11 11:25:19,563 CassandraDaemon.java (line 164) Exception in thread Thread[Thrift:641,5,main] ... INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,915 ThriftServer.java (line 116) Stop listening to thrift clients INFO [StorageServiceShutdownHook] 2013-04-11 11:25:39,943 Gossiper.java (line 1077) Announcing shutdown INFO [StorageServiceShutdownHook] 2013-04-11 11:26:08,613 MessagingService.java (line 682) Waiting for messaging service to quiesce INFO [ACCEPT-/208.94.232.37] 2013-04-11 11:26:08,655 MessagingService.java (line 888) MessagingService shutting down server thread. ERROR [Thrift:721] 2013-04-11 11:26:37,709 CustomTThreadPoolServer.java (line 217) Error occurred during processing of message. java.util.concurrent.RejectedExecutionException: ThreadPoolExecutor has shut down Anyone have some advices about better utilization of such servers? Nick.
Does Memtable resides in Heap?
Hi Team, I have got this 8GB of RAM out of that 4GB allocated to Java Heap. My question is the size of Memtable does it contribute to heap size? or they are part of off-heap? Does bigger Memtable would have impact on GC and overall memory management? I am using DSE 3.0 / Cassandra 1.1.9. Thanks, Jay
Broken pipe when variating a lot number of connections
Hi, I've been changing a benchmarking tool (YCSB) to vary the number of clients throughout a workload execution and, for some reason, I believe Cassandra is facing some problems to handle the variation (both up and down) on the number of connections. Each client has a connection and clients are added or removed during execution. For some reason, after some (variable) time, I get the following exception, using the original Cassandra client implemented by YCSB, that works for a constant number of clients. Is there any reason or known issue to explain why cassandra does not handle properly the number of connection and gives broken pipe? I'm supposing this can be a Cassandra problem, but feel free to let me know if you think I'm wrong. Thanks in advance. *Cassandra version:* 1.1.5 *Some property values:* - rpc_keepalive: true - rpc_min_threads: 16 - rpc_max_threads: 2048 *Exception:* *Changing clients from 192 to 240* *org.apache.thrift.transport.TTransportException: java.net.SocketException: Broken pipe* *org.apache.thrift.transport.TTransportException: java.net.SocketException: Broken pipe* * at org.apache.thrift.transport.TIOStreamTransport.flush(TIOStreamTransport.java:161) * * at org.apache.thrift.transport.TFramedTransport.flush(TFramedTransport.java:158) * * at org.apache.cassandra.thrift.Cassandra$Client.send_set_keyspace(Cassandra.java:436) * * at org.apache.cassandra.thrift.Cassandra$Client.set_keyspace(Cassandra.java:425) * * at com.yahoo.ycsb.db.CassandraClient10.scan(CassandraClient10.java:314)* * at com.yahoo.ycsb.DBWrapper.scan(DBWrapper.java:106)* * at com.yahoo.ycsb.workloads.CoreWorkload.doTransactionScan(CoreWorkload.java:530) * * at com.yahoo.ycsb.workloads.CoreWorkload.doTransaction(CoreWorkload.java:431)* * at com.yahoo.ycsb.ClientThread.run(ClientThread.java:105)* Att. *Rodrigo Felix de Almeida* LSBD - Universidade Federal do Ceará Project Manager MBA, CSM, CSPO, SCJP
Re: CorruptedBlockException
Saw this in earlier versions. Our workaround was disable; drain; snap;
shutdown; delete; link from snap; restart;
-ljr
On Apr 11, 2013, at 9:45, moshe.kr...@barclays.com wrote:
I have formulated the following theory regarding C* 1.2.2 which may be
relevant: Whenever there is a disk error during compaction of an SS table
(e.g., bad block, out of disk space), that SStable’s files stick around
forever after, and do not subsequently get deleted by normal compaction
(minor or major), long after all its records have been deleted. This causes
disk usage to rise dramatically. The only way to make the SStable files
disappear is to run “nodetool cleanup” (which takes hours to run).
Just a theory so far….
From: Alexis Rodríguez [mailto:arodrig...@inconcertcc.com]
Sent: Thursday, April 11, 2013 5:31 PM
To: user@cassandra.apache.org
Subject: Re: CorruptedBlockException
Aaron,
It seems that we are in the same situation as Nury, we are storing a lot of
files of ~5MB in a CF.
This happens in a test cluster, with one node using cassandra 1.1.5, we have
commitlog in a different partition than the data directory. Normally our
tests use nearly 13 GB in data, but when the exception on compaction appears
our disk space ramp up to:
# df -h
FilesystemSize Used Avail Use% Mounted on
/dev/sda1 440G 330G 89G 79% /
tmpfs 7.9G 0 7.9G 0% /lib/init/rw
udev 7.9G 160K 7.9G 1% /dev
tmpfs 7.9G 0 7.9G 0% /dev/shm
/dev/sdb1 459G 257G 179G 59% /cassandra
# cd /cassandra/data/Repository/
# ls Files/*tmp* | wc -l
1671
# du -ch Files | tail -1
257Gtotal
# du -ch Files/*tmp* | tail -1
34G total
We are using cassandra 1.1.5 with one node, our schema for that keyspace is:
[default@unknown] use Repository;
Authenticated to keyspace: Repository
[default@Repository] show schema;
create keyspace Repository
with placement_strategy = 'NetworkTopologyStrategy'
and strategy_options = {datacenter1 : 1}
and durable_writes = true;
use Repository;
create column family Files
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'BytesType'
and key_validation_class = 'BytesType'
and read_repair_chance = 0.1
and dclocal_read_repair_chance = 0.0
and gc_grace = 864000
and min_compaction_threshold = 4
and max_compaction_threshold = 32
and replicate_on_write = true
and compaction_strategy =
'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'
and caching = 'KEYS_ONLY'
and compaction_strategy_options = {'sstable_size_in_mb' : '120'}
and compression_options = {'sstable_compression' :
'org.apache.cassandra.io.compress.SnappyCompressor'};
In our logs:
ERROR [CompactionExecutor:1831] 2013-04-11 09:12:41,725
AbstractCassandraDaemon.java (line 135) Exception in thread
Thread[CompactionExecutor:1831,1,main]
java.io.IOError: org.apache.cassandra.io.compress.CorruptedBlockException:
(/cassandra/data/Repository/Files/Repository-Files-he-4533-Data.db):
corruption detected, chunk at 43325354 of length 65545.
at
org.apache.cassandra.db.compaction.PrecompactedRow.merge(PrecompactedRow.java:116)
at
org.apache.cassandra.db.compaction.PrecompactedRow.init(PrecompactedRow.java:99)
at
org.apache.cassandra.db.compaction.CompactionController.getCompactedRow(CompactionController.java:176)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:83)
at
org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:68)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.consume(MergeIterator.java:118)
at
org.apache.cassandra.utils.MergeIterator$ManyToOne.computeNext(MergeIterator.java:101)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at
com.google.common.collect.Iterators$7.computeNext(Iterators.java:614)
at
com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:140)
at
com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:135)
at
org.apache.cassandra.db.compaction.CompactionTask.execute(CompactionTask.java:173)
at
org.apache.cassandra.db.compaction.LeveledCompactionTask.execute(LeveledCompactionTask.java:50)
at
org.apache.cassandra.db.compaction.CompactionManager$1.runMayThrow(CompactionManager.java:154)
at
org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:30)
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
RE: Does Memtable resides in Heap?
Memtables resides in heap, write rate impacts GC, more writes - more frequent and longer ParNew GC pauses. From: Jay Svc [mailto:jaytechg...@gmail.com] Sent: Friday, April 12, 2013 01:03 To: user@cassandra.apache.org Subject: Does Memtable resides in Heap? Hi Team, I have got this 8GB of RAM out of that 4GB allocated to Java Heap. My question is the size of Memtable does it contribute to heap size? or they are part of off-heap? Does bigger Memtable would have impact on GC and overall memory management? I am using DSE 3.0 / Cassandra 1.1.9. Thanks, Jay Best regards / Pagarbiai Viktor Jevdokimov Senior Developer Email: viktor.jevdoki...@adform.com Phone: +370 5 212 3063 Fax: +370 5 261 0453 J. Jasinskio 16C, LT-01112 Vilnius, Lithuania Disclaimer: The information contained in this message and attachments is intended solely for the attention and use of the named addressee and may be confidential. If you are not the intended recipient, you are reminded that the information remains the property of the sender. You must not use, disclose, distribute, copy, print or rely on this e-mail. If you have received this message in error, please contact the sender immediately and irrevocably delete this message and any copies.
RE: multiple Datacenter values in PropertyFileSnitch
I´m using for each application it´s own keyspace. What I want is to split up for different load patterns. So that 2 apps with same and very high load pattern are not clashing. For other load patterns I want to use another splitting. Is there any best practice or should I scale out, so that the complete load can be distributed to on all nodes? Br, Matthias Zeilinger Production Operation - Shared Services P: +43 (0) 50 858-31185 M: +43 (0) 664 85-34459 E: matthias.zeilin...@bwinparty.com bwin.party services (Austria) GmbH Marxergasse 1B A-1030 Vienna www.bwinparty.com From: aaron morton [mailto:aa...@thelastpickle.com] Sent: Donnerstag, 11. April 2013 20:48 To: user@cassandra.apache.org Subject: Re: multiple Datacenter values in PropertyFileSnitch A node can only exist in one DC and one rack. Use different keyspaces as suggested. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 12/04/2013, at 1:47 AM, Jabbar Azam aja...@gmail.commailto:aja...@gmail.com wrote: Hello, I'm not an expert but I don't think you can do what you want. The way to separate data for applications on the same cluster is to use different tables for different applications or use multiple keyspaces, a keyspace per application. The replication factor you specify for each keyspace specifies how many copies of the data are stored in each datacenter. You can't specify that data for a particular application is stored on a specific node, unless that node is in its own cluster. I think of a cassandra cluster as a shared resource where all the applications have access to all the nodes in the cluster. Thanks Jabbar Azam On 11 April 2013 14:13, Matthias Zeilinger matthias.zeilin...@bwinparty.commailto:matthias.zeilin...@bwinparty.com wrote: Hi, I would like to create big cluster for many applications. Within this cluster I would like to separate the data for each application, which can be easily done via different virtual datacenters and the correct replication strategy. What I would like to know, if I can specify for 1 node multiple values in the PropertyFileSnitch configuration, so that I can use 1 node for more applications? For example: 6 nodes: 3 for App A 3 for App B 4 for App C I want to have such a configuration: Node 1 - DC-A DC-C Node 2 - DC-B DC-C Node 3 - DC-A DC-C Node 4 - DC-B DC-C Node 5 - DC-A Node 6 - DC-B Is this possible or does anyone have another solution for this? Thx br matthias
