Why do you think the amount of partitions is different in these tables? The
partition key is the same (system_name and event_name). The number of rows per
partition is different.
From: kurt Greaves [mailto:k...@instaclustr.com]
Sent: Thursday, June 09, 2016 7:52 AM
To:
s replacing. My new solution goes back to my old solution.
On Thu, Apr 7, 2016 at 1:37 AM, Peer, Oded
<oded.p...@rsa.com<mailto:oded.p...@rsa.com>> wrote:
I have a table mapping continuous ranges to discrete values.
CREATE TABLE range_mapping (k int, lower int, upper int, mapped_
I have a table mapping continuous ranges to discrete values.
CREATE TABLE range_mapping (k int, lower int, upper int, mapped_value int,
PRIMARY KEY (k, lower, upper));
INSERT INTO range_mapping (k, lower, upper, mapped_value) VALUES (0, 0, 99, 0);
INSERT INTO range_mapping (k, lower, upper,
ould I “unset” a field inside the JSON message written to the
event_by_patient_timestamp table?
Ralf
On 24.03.2016, at 10:22, Peer, Oded
<oded.p...@rsa.com<mailto:oded.p...@rsa.com>> wrote:
http://www.datastax.com/dev/blog/datastax-java-driver-3-0-0-released#unset-values
“For Protoco
http://www.datastax.com/dev/blog/datastax-java-driver-3-0-0-released#unset-values
"For Protocol V3 or below, all variables in a statement must be bound. With
Protocol V4, variables can be left "unset", in which case they will be ignored
server-side (no tombstones will be generated)."
From:
You can change the table to support Multi-column slice restrictions
CREATE TABLE routes (
start text,
end text,
year int,
month int,
day int,
PRIMARY KEY (start, end, year, month, day)
);
Then using Multi-column slice restrictions you can query:
SELECT * from routes where start = 'New York' and
I read the documentation for restoring a snapshot into a new cluster.
It got me thinking about replica placement in that context.
"NetworkTopologyStrategy places replicas in the same data center by walking the
ring clockwise until reaching the first node in another rack."
It seems it is not
Ramon,
Have you tried another driver to determine if the problem is in the Python
driver?
You can deserialize your composite key using the following code:
ByteBuffer t =
ByteBufferUtil.hexToBytes("0008000e70451f6404000500");
short periodlen =
It might be a consistency issue.
Assume your data for tnt 5 should be on nodes 1 and 2, but actually never got
to node 1 for various reasons, and the hint wasn’t replayed for some reason and
you didn’t run repairs. The data for tnt 5 is only on node 2.
A query without restrictions on the
Have you read the DataStax documentation?
http://docs.datastax.com/en/cassandra/2.0/cassandra/operations/ops_snapshot_restore_new_cluster.html
From: Romain Hardouin [mailto:romainh...@yahoo.fr]
Sent: Wednesday, November 18, 2015 3:59 PM
To: user@cassandra.apache.org
Subject: Re: Strategy tools
See https://issues.apache.org/jira/browse/CASSANDRA-7910
From: joseph gao [mailto:gaojf.bok...@gmail.com]
Sent: Wednesday, August 26, 2015 6:15 AM
To: user@cassandra.apache.org
Subject: Re: PrepareStatement BUG
Hi, anybody knows how to resolve this problem?
2015-08-23 1:35 GMT+08:00 joseph gao
HEAP_NEWSIZE=1600M
But I am still unable to start the server properly. But this time system.log
has bit different logs.
https://gist.github.com/cdwijayarathna/75f65a34d9e71829adaa
Any idea on how to proceed?
Thanks
On Wed, Jul 22, 2015 at 11:54 AM, Peer, Oded
oded.p...@rsa.commailto:oded.p
Setting system_memory_in_mb to 16 GB means the Cassandra heap size you are
using is 4 GB.
If you meant to use a 16GB heap you should uncomment the line
#MAX_HEAP_SIZE=4G
And set
MAX_HEAP_SIZE=16G
You should uncomment the HEAP_NEWSIZE setting as well. I would leave it with
the default setting
Cassandra is a highly scalable, eventually consistent, distributed, structured
key-value store http://wiki.apache.org/cassandra/
It is intended for searching by key. It has more querying options but it really
shines when querying by key.
Not all databases offer the same functionality. Both a
...@gmail.commailto:cdwijayarat...@gmail.com wrote:
Hi Peer,
https://gist.githubusercontent.com/cdwijayarathna/a14586a9e39a943f89a0/raw/system%20log
This is the log of the last time I started the server, I couldn't found any
error there.
Thanks
On Sun, Jul 19, 2015 at 5:56 PM, Peer, Oded
oded.p
Are you sure your node is up? Do you get a result when running “nodetool –h
192.248.15.219 status”?
From: Chamila Wijayarathna [mailto:cdwijayarat...@gmail.com]
Sent: Sunday, July 19, 2015 1:53 PM
To: user@cassandra.apache.org
Subject: Re: Can't connect to Cassandra server
Hi Umang,
Tried your
$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
What is the reason for this? How can I fix this?
Thank You!
On Sun, Jul 19, 2015 at 4:52 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
Are you sure your node is up? Do you get a result
The data model suggested isn’t optimal for the “end of month” query you want to
run since you are not querying by partition key.
The query would look like “select EmpID, FN, LN, basic from salaries where
month = 1” which requires filtering and has unpredictable performance.
For this type of
I get the alter table message? How can I get and deal
that message?
2015-06-15 16:45 GMT+08:00 Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com:
This only applies to “select *” queries where you don’t specify the column
names.
There is a reported bug and fixed in 2.1.3. See
https
This only applies to “select *” queries where you don’t specify the column
names.
There is a reported bug and fixed in 2.1.3. See
https://issues.apache.org/jira/browse/CASSANDRA-7910
From: joseph gao [mailto:gaojf.bok...@gmail.com]
Sent: Monday, June 15, 2015 10:52 AM
To:
13, 2015 at 3:45 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
Under the assumption that when you update the columns you also update the TTL
for the columns then a tombstone won’t be created for those columns.
Remember that TTL is set on columns (or “cells”), not on rows, so
You can use the “last modified” value as the TIMESTAMP for your UPDATE
operation.
This way the values will only be updated if lastModified date the
lastModified you have in the DB.
Updates to values don’t create tombstones. Only deletes (either by executing
delete, inserting a null value or
Under the assumption that when you update the columns you also update the TTL
for the columns then a tombstone won't be created for those columns.
Remember that TTL is set on columns (or cells), not on rows, so your
description of updating a row is slightly misleading. If every query updates
are present in queries), then is there no cost to just submitting an
update for everything regardless of whether lastModified has changed?
Thanks.
On Wed, May 13, 2015 at 3:38 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
You can use the “last modified” value as the TIMESTAMP
unless the timestamp is
actually last update timestamp?)
Also, is there a way to get the number of rows which were updated / ignored?
On Wed, May 13, 2015 at 4:37 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
The cost of issuing an UPDATE that won’t update anything is compaction
, or will they be
ignored?
E.g if I issued an update where TIMESTAMP is X, then 1 hour later I issued
another update where TIMESTAMP is still X, will that 2nd update essentially get
ignored, or will it cause any overhead?
On Wed, May 13, 2015 at 5:02 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote
I’ve added an option to prevent tombstone creation when using
PreparedStatements to trunk, see CASSANDRA-7304.
The problem is having tombstones in regular columns.
When you perform a read request (range query or by PK):
- Cassandra iterates over all the cells (all, not only the cells specified
In general your data model should match your queries in Cassandra.
In the examples you provided the queries are by name, not by ID, so I don’t see
much use in using ID as the primary key.
Without much context, like why you are using SET or if queries must specify
both first_name and last_name
Inserting a null value creates a tombstone. Tombstones can have major
performance implications.
You can see the tombstones using sstable2json.
If you have a small number of records with null values this seems OK, otherwise
I recommend using the QueryBuilder (for Java clients) and waiting for
See https://github.com/apache/cassandra/blob/trunk/NEWS.txt#L173
SSTable data directory name is slightly changed. Each directory will have hex
string appended after CF name, e.g. ks/cf-5be396077b811e3a3ab9dc4b9ac088d/
This hex string part represents unique ColumnFamily ID.
Note that existing
).
Thanks.
On Sun, Apr 26, 2015 at 1:29 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
I would maintain two tables.
An “archive” table that holds all the active and inactive records, and is
updated hourly (re-inserting the same record has some compaction overhead but
on the other
I would maintain two tables.
An “archive” table that holds all the active and inactive records, and is
updated hourly (re-inserting the same record has some compaction overhead but
on the other side deleting records has tombstones overhead).
An “active” table which holds all the records in the
On Tue, Mar 31, 2015 at 7:42 AM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
Thanks Sylvain.
Is there any way to create a composite key with only one column in Cassandra
when creating a table, or should creating a CompositeType instance with a
single column be prohibited?
It's
I am writing code to bulk load data into Cassandra using
SSTableSimpleUnsortedWriter
I changed my partition key from a composite key (long, int) to a single column
key (long).
For creating the composite key I used a CompositeType, and I kept using it
after changing the key to a single column.
class javadoc if
you're interested. It's not the most compact format there is but changing it
would break backward compatibility anyway.
On Mon, Mar 30, 2015 at 12:38 PM, Peer, Oded
oded.p...@rsa.commailto:oded.p...@rsa.com wrote:
I am writing code to bulk load data into Cassandra using
Try this
http://stackoverflow.com/a/17208343/248656
From: jean paul [mailto:researche...@gmail.com]
Sent: Wednesday, March 18, 2015 7:06 PM
To: user@cassandra.apache.org
Subject: Saving a file using cassandra
Hello,
Finally, i have created my ring using cassandra.
Please, i'd like to store a
My intended Cassandra cluster will have 15 nodes per DC, with 2 DCs.
I am considering using all the nodes as seed nodes.
It looks like having all the nodes as seeds should actually reduce the Gossip
overhead (See Gossiper implementation in
http://wiki.apache.org/cassandra/ArchitectureGossip)
Is
Thank you Aaaron!
Your blog post helped me understand how a row with a compound key is stored and
this helped me understand how to create the sstable files.
For anyone who needs it this is how it works:
In Cassandra-cli the row looks like this:
RowKey: 5
= (column=10:created,
Hi,
I am using Cassandra 1.2.5. I built a cluster of 2 data centers with 3 nodes in
each data center.
I created a key space and table with a composite key:
create keyspace test_keyspace WITH replication = {'class':
'NetworkTopologyStrategy', 'DC1' : 1, 'DC2' : 1};
create table test_table
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