Re: Filter data on row key in Cassandra Hadoop's Random Partitioner
You can use Apache PIG to load data and filter it by row key, filter in pig is very fast. Regards Shamim 11.12.2012, 20:46, Ayush V. ayushv...@gmail.com: I'm working on Cassandra Hadoop intergration (MapReduce). We have used Random Partioner to insert data to gain faster write. Now we have to read that data from cassandra in MapReduce and perform some calculation on it. From the lots of data we have in cassandra we wan't to fetch data only for particular ROW-KEYs but we are unable to do it due to RandomPartioner - assertion is there in code. Can anyone please guide me how should I filter data based on RowKey on Cassandra level itself (I know data is distributed across regions using Hash of the RowKey)? Does using secondary indexes (still trying to understand how it works) will solve my problem or is there some other way around? I will be really appreciated if someone could answer my queries. Thanks AV -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Filter-data-on-row-key-in-Cassandra-Hadoop-s-Random-Partitioner-tp7584212.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.
RE: cassandra vs couchbase benchmark
Pure marketing comparing apples to oranges. Was Cassandra usage optimized? - What consistency level was used? (fastest reads with ONE) - Does Cassandra client used was token aware? (make request to appropriate node) - Was dynamic snitch turned off? (prevent forward request to other replica if can be processed locally) - Does Cassandra data model was used to mimic Couchbase data model? (Couchbase has only 1 value for 1 row) - What caching was used on Cassandra? (Couchbase uses memcache built-in) For our use case we've seen much better results upon testing from single node. Throughput grows almost linearly adding nodes and growing amount of data to the same level as for single node. Single node stats: - A column family with 30 GiB compressed data per node (100 GiB uncompressed) - 1 row with 10-30 columns weighted 0.5-2 KiB uncompressed - 1 node with 6 cores 24 GiB RAM, 8 GiB heap, 1600 MiB new heap - key cache only, 2M keys - random reads 70%, random writes 30% - Read latencies 10ms AVE100 with CPU 95%, 50k reads/s - Read latencies 5ms AVE100 with CPU 60%, 20k reads/s In reality, with many column families with different amount of data, read/write rates, performance results may significantly vary. Just need to know what and how to optimize for Cassandra to get best results. Couchbase is not for our use case because of its data model (requires reads for updates/inserts), so we can't compare it to Cassandra. 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. -Original Message- From: Radim Kolar [mailto:h...@filez.com] Sent: Tuesday, December 11, 2012 17:42 To: user@cassandra.apache.org Subject: cassandra vs couchbase benchmark http://www.slideshare.net/Couchbase/benchmarking-couchbase#btnNext
Re: Batch mutation streaming
Hey Aaron, That sounds sensible - thanks for the heads up. Cheers, Ben On Dec 10, 2012, at 0:47, aaron morton aa...@thelastpickle.com wrote: (and if the message is being decoded on the server site as a complete message, then presumably the same resident memory consumption applies there too). Yerp. And every row mutation in your batch becomes a task in the Mutation thread pool. If one replica gets 500 row mutations from one client request it will take a while for the (default) 32 threads to chew through them. While this is going on other client request will be effectively blocked. Depending on the number of clients, I would start with say 50 rows per mutation and keep and eye of the *request* latency. Hope that helps. - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 9/12/2012, at 7:18 AM, Ben Hood 0x6e6...@gmail.com wrote: Thanks for the clarification Andrey. If that is the case, I had better ensure that I don't put the entire contents of a very long input stream into a single batch, since that is presumably going to cause a very large message to accumulate on the client side (and if the message is being decoded on the server site as a complete message, then presumably the same resident memory consumption applies there too). Cheers, Ben On Dec 7, 2012, at 17:24, Andrey Ilinykh ailin...@gmail.com wrote: Cassandra uses thrift messages to pass data to and from server. A batch is just a convenient way to create such message. Nothing happens until you send this message. Probably, this is what you call close the batch. Thank you, Andrey On Fri, Dec 7, 2012 at 5:34 AM, Ben Hood 0x6e6...@gmail.com wrote: Hi, I'd like my app to stream a large number of events into Cassandra that originate from the same network input stream. If I create one batch mutation, can I just keep appending events to the Cassandra batch until I'm done, or are there some practical considerations about doing this (e.g. too much stuff buffering up on the client or server side, visibility of the data within the batch that hasn't been closed by the client yet)? Barring any discussion about atomicity, if I were able to stream a largish source into Cassandra, what would happen if the client crashed and didn't close the batch? Or is this kind of thing just a normal occurrence that Cassandra has to be aware of anyway? Cheers, Ben
Re: Why Secondary indexes is so slowly by my test?
You could always try PlayOrm's query capability on top of cassandra ;)….it
works for us.
Dean
From: Chengying Fang cyf...@ngnsoft.commailto:cyf...@ngnsoft.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, December 11, 2012 8:22 PM
To: user user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: Why Secondary indexes is so slowly by my test?
Thanks to Low. We use CompositeColumn to substitue it in single not-equality
and definite equalitys query. And we will give up cassandra because of the weak
query ability and unstability. Many times, we found our data in confusion
without definite cause in our cluster. For example, only two rows in one CF,
row1-columnname1-columnvalue1,row2-columnname2-columnvalue2, but some times, it
becomes row1-columnname1-columnvalue2,row2-columnname2-columnvalue1. Notice the
wrong column value.
-- Original --
From: Richard Lowr...@acunu.commailto:r...@acunu.com;
Date: Tue, Dec 11, 2012 07:44 PM
To: useruser@cassandra.apache.orgmailto:user@cassandra.apache.org;
Subject: Re: Why Secondary indexes is so slowly by my test?
Hi,
Secondary index lookups are more complicated than normal queries so will be
slower. Items have to first be queried in the index, then retrieved from their
actual location. Also, inserting into indexed CFs will be slower (but will get
substantially faster in 1.2 due to CASSANDRA-2897).
If you need to retrieve large amounts of data with your query, you would be
better off changing your data model to not use secondary indexes.
Richard.
On 7 December 2012 03:08, Chengying Fang
cyf...@ngnsoft.commailto:cyf...@ngnsoft.com wrote:
Hi guys,
I found Secondary indexes too slowly in my product(amazon large instance) with
cassandra, then I did test again as describe here. But the result is the same
as product. What's wrong with cassandra or me?
Now my test:
newly installed ubuntu-12.04 LTS , apache-cassandra-1.1.6, default configure,
just one keyspace(test) and one CF(TestIndex):
1. CREATECOLUMN FAMILY TestIndex
2. WITH comparator = UTF8Type
3. AND key_validation_class=UTF8Type
4. AND default_validation_class = UTF8Type
5. AND column_metadata = [
6. {column_name: tk, validation_class: UTF8Type, index_type: KEYS}
7. {column_name: from, validation_class: UTF8Type}
8. {column_name: to, validation_class: UTF8Type}
9. {column_name: tm, validation_class: UTF8Type}
10. ];
and 'tk' just three value:'A'(1000row),'B'(1000row),'X'(increment by test)
The test query from cql:
1,without index:selectcount(*) from TestIndex limit 100;
2,with index:selectcount(*) from TestIndex where tk='X' limit 100;
When I insert 6 row 'X', the time:1s and 12s.
When 'X' up to 13,the time:2.3s and 33s.
When 'X' up to 25,the time:3.8s and 53s.
According to this, when 'X' up to billon, what's the result? Can Secondary
indexes be used in product? I hope it's my mistake in doing this test.Can
anyone give some tips about it?
Thanks in advance.
fancy
--
Richard Low
Acunu | http://www.acunu.com | @acunu
Re: Vnode migration path
On Tue, Dec 11, 2012 at 4:28 PM, Michael Kjellman mkjell...@barracuda.com wrote: Awesome (and very welcomed news), what kind of failure conditions can we expect if a node goes down during the migration? A shuffle is just a bunch of moves mapped out ahead of time, and worked through by each node incrementally. These mappings are persisted, so a node that went down during a shuffle would simply pick back up where it left off when it came back online. A node irrecoverably failing mid-shuffle would likely require some intervention to sort out. Either way, there won't be any other impact to the cluster beyond what is normally caused by a down node. From: Richard Low r...@acunu.com Reply-To: user@cassandra.apache.org user@cassandra.apache.org Date: Tuesday, December 11, 2012 3:33 AM To: user@cassandra.apache.org user@cassandra.apache.org Subject: Re: Vnode migration path Hi Mike, There's also the shuffle utility (in the bin directory) that can incrementally move ranges around to migrate to vnodes. Richard. On 11 December 2012 08:47, Michael Kjellman mkjell...@barracuda.com wrote: So I'm wondering if anyone has given thought to their migration path to Vnodes. Other than having a separate cluster and migrating the data from the old cluster to the vnode cluster what else can we do. One suggestion I've heard is start up a second Cassandra instance on each node on different ports and migrate between nodes that way. Best, mike 'Like' us on Facebook for exclusive content and other resources on all Barracuda Networks solutions. Visit http://barracudanetworks.com/facebook -- Richard Low Acunu | http://www.acunu.com | @acunu -- 'Like' us on Facebook for exclusive content and other resources on all Barracuda Networks solutions. Visit http://barracudanetworks.com/facebook -- Eric Evans Acunu | http://www.acunu.com | @acunu
Null Error Running pig_cassandra
When trying to run the example-script.pig, I get the following error, null error. tsunami:pig schappetj$ bin/pig_cassandra -x local example-script.pig Using /Library/pig-0.10.0/pig-0.10.0.jar. 2012-12-12 11:02:54,079 [main] INFO org.apache.pig.Main - Apache Pig version 0.10.0 (r1328203) compiled Apr 20 2012, 00:33:25 2012-12-12 11:02:54,079 [main] INFO org.apache.pig.Main - Logging error messages to: /Library/apache-cassandra-1.2.0-beta3-src/examples/pig/pig_1355331774074.log 2012-12-12 11:02:54.211 java[78283:1c03] Unable to load realm info from SCDynamicStore 2012-12-12 11:02:54,400 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:/// 2012-12-12 11:02:54,890 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1200: null Details at logfile: /Library/apache-cassandra-1.2.0-beta3-src/examples/pig/pig_1355331774074.log PIG 0.10.0 Cassandra 1.2.0-Beta3 w/source ENV Osx Lion: $ java -version java version 1.7.0_04 Java(TM) SE Runtime Environment (build 1.7.0_04-b21) Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode) set | grep PIG PIG_HOME=/Library/pig-0.10.0 PIG_INITIAL_ADDRESS=localhost PIG_PARTITIONER=org.apache.cassandra.dht.RandomPartitioner PIG_RPC_PORT=9160 Pig Stack Trace --- ERROR 1200: null org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1000: Error during parsing. null at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1597) at org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:1540) at org.apache.pig.PigServer.registerQuery(PigServer.java:540) at org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:970) at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser. java:386) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:189 ) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:165 ) at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84) at org.apache.pig.Main.run(Main.java:555) at org.apache.pig.Main.main(Main.java:111) 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:601) at org.apache.hadoop.util.RunJar.main(RunJar.java:156) Caused by: Failed to parse: null at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:184) at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1589) ... 14 more Caused by: java.lang.NullPointerException at org.apache.cassandra.utils.Hex.hexToBytes(Hex.java:51) at org.apache.cassandra.hadoop.ConfigHelper.predicateFromString(ConfigHelper.ja va:206) at org.apache.cassandra.hadoop.ConfigHelper.getInputSlicePredicate(ConfigHelper .java:176) at org.apache.cassandra.hadoop.pig.CassandraStorage.setLocation(CassandraStorag e.java:577) at org.apache.cassandra.hadoop.pig.CassandraStorage.getSchema(CassandraStorage. java:610) at org.apache.pig.newplan.logical.relational.LOLoad.getSchemaFromMetaData(LOLoa d.java:151) at org.apache.pig.newplan.logical.relational.LOLoad.getSchema(LOLoad.java:110) at org.apache.pig.parser.LogicalPlanGenerator.alias_col_ref(LogicalPlanGenerato r.java:15356) at org.apache.pig.parser.LogicalPlanGenerator.col_ref(LogicalPlanGenerator.java :15203) at org.apache.pig.parser.LogicalPlanGenerator.projectable_expr(LogicalPlanGener ator.java:8881) at org.apache.pig.parser.LogicalPlanGenerator.var_expr(LogicalPlanGenerator.jav a:8632) at org.apache.pig.parser.LogicalPlanGenerator.expr(LogicalPlanGenerator.java:79 84) at org.apache.pig.parser.LogicalPlanGenerator.flatten_clause(LogicalPlanGenerat or.java:6103) at org.apache.pig.parser.LogicalPlanGenerator.flatten_generated_item(LogicalPla nGenerator.java:5926) at org.apache.pig.parser.LogicalPlanGenerator.generate_clause(LogicalPlanGenera tor.java:14101) at org.apache.pig.parser.LogicalPlanGenerator.foreach_plan(LogicalPlanGenerator .java:12493) at org.apache.pig.parser.LogicalPlanGenerator.foreach_clause(LogicalPlanGenerat or.java:12360) at org.apache.pig.parser.LogicalPlanGenerator.op_clause(LogicalPlanGenerator.ja va:1577) at org.apache.pig.parser.LogicalPlanGenerator.general_statement(LogicalPlanGene rator.java:789) at org.apache.pig.parser.LogicalPlanGenerator.statement(LogicalPlanGenerator.ja va:507) at org.apache.pig.parser.LogicalPlanGenerator.query(LogicalPlanGenerator.java:3 82) at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:175) ... 15 more
Re: Cassandra on EC2 - describe_ring() is giving private IPs
When I configured rpc_address with public IP, cassandra is not starting up. It's trowing 'unable to create thrift socket on public IP. When I changed it to private IP, it was good. java.lang.RuntimeException: Unable to create thrift socket to / 107.21.80.94:9160 at org.apache.cassandra.thrift.CassandraDaemon$ThriftServer.init(CassandraDaemon.java:148) at org.apache.cassandra.thrift.CassandraDaemon.startServer(CassandraDaemon.java:76) at org.apache.cassandra.service.AbstractCassandraDaemon.startRPCServer(AbstractCassandraDaemon.java:300) at org.apache.cassandra.service.AbstractCassandraDaemon.start(AbstractCassandraDaemon.java:272) at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:369) at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:107) Caused by: org.apache.thrift.transport.TTransportException: Could not create ServerSocket on address /107.21.80.94:9160. at org.apache.cassandra.thrift.TCustomServerSocket.init(TCustomServerSocket.java:80) at org.apache.cassandra.thrift.CassandraDaemon$ThriftServer.init(CassandraDaemon.java:141) On Wed, Dec 12, 2012 at 3:34 AM, aaron morton aa...@thelastpickle.comwrote: Though I configured the listen_address with public dns, still I had the same issue. Internally the public DNS resolves to the private IP. looks like describe_ring() is the one which provides the details. describe_ring() returns includes the registered RPC addresses for the nodes. Trying setting the rpc_address to the public IP. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 11/12/2012, at 11:32 PM, santi kumar santi.ku...@gmail.com wrote: We have a 4 node cluster in us-east region in two different AZ's. Clients connect to this cluster from our datacenter which is not on AWS. Hector clients are initialized with public DNS names, then listern_address is with private ip and rpc_address is with 0.0.0.0. Having issues with Node Auto Discovery by Hector. When it's trying to discover the ring, the end points are initialized with private IP's for all Token Ranges. It checks with the existing hosts (which are initialized public DNS) and thinks that there is a new node got added to the cluster. looks like describe_ring() is the one which provides the details. Though I configured the listen_address with public dns, still I had the same issue. Any idea, what is the best way to configure for EC2. Have gone through the link https://docs.google.com/document/d/175duUNIx7m5mCDa2sjXVI04ekyMa5bdiWdu-AFgisaY/edit?hl=en But not sure whether it's fixed in 1.1.4. When I run the nodetool ring, it gives the private ips. But in the above doc, it shows the public IPs as part of nodetool ring. Some insight into this is really helpful. Thanks Santi
Re: cassandra vs couchbase benchmark
if dataset fits into memory and data used in test almost fits into memory then cassandra is slow compared to other leading nosql databases, it can go up to 10:1 ratio. Check infinispan benchmarks. Common use pattern is to use memcached on top of cassandra. cassandra is good if you have way more data then your RAM size. It beats SQL database 10:1 ratio at cost low flexibility for queries.
Re: Cassandra on EC2 - describe_ring() is giving private IPs
Yes That worked. Thanks for the pointer. Once the broadcast_address is pointed to public IP, end points are coming with public IP. so Hectors NodeAutoDiscoveryService matches with the existing host and not treating it as new node. On Wed, Dec 12, 2012 at 11:10 PM, Andrey Ilinykh ailin...@gmail.com wrote: It makes sense. rpc_address is interface to listen. Try to set up public IP to broadcast_address. Andrey On Wed, Dec 12, 2012 at 9:33 AM, santi kumar santi.ku...@gmail.comwrote: When I configured rpc_address with public IP, cassandra is not starting up. It's trowing 'unable to create thrift socket on public IP. When I changed it to private IP, it was good. java.lang.RuntimeException: Unable to create thrift socket to / 107.21.80.94:9160 at org.apache.cassandra.thrift.CassandraDaemon$ThriftServer.init(CassandraDaemon.java:148) at org.apache.cassandra.thrift.CassandraDaemon.startServer(CassandraDaemon.java:76) at org.apache.cassandra.service.AbstractCassandraDaemon.startRPCServer(AbstractCassandraDaemon.java:300) at org.apache.cassandra.service.AbstractCassandraDaemon.start(AbstractCassandraDaemon.java:272) at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:369) at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:107) Caused by: org.apache.thrift.transport.TTransportException: Could not create ServerSocket on address /107.21.80.94:9160. at org.apache.cassandra.thrift.TCustomServerSocket.init(TCustomServerSocket.java:80) at org.apache.cassandra.thrift.CassandraDaemon$ThriftServer.init(CassandraDaemon.java:141) On Wed, Dec 12, 2012 at 3:34 AM, aaron morton aa...@thelastpickle.comwrote: Though I configured the listen_address with public dns, still I had the same issue. Internally the public DNS resolves to the private IP. looks like describe_ring() is the one which provides the details. describe_ring() returns includes the registered RPC addresses for the nodes. Trying setting the rpc_address to the public IP. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 11/12/2012, at 11:32 PM, santi kumar santi.ku...@gmail.com wrote: We have a 4 node cluster in us-east region in two different AZ's. Clients connect to this cluster from our datacenter which is not on AWS. Hector clients are initialized with public DNS names, then listern_address is with private ip and rpc_address is with 0.0.0.0. Having issues with Node Auto Discovery by Hector. When it's trying to discover the ring, the end points are initialized with private IP's for all Token Ranges. It checks with the existing hosts (which are initialized public DNS) and thinks that there is a new node got added to the cluster. looks like describe_ring() is the one which provides the details. Though I configured the listen_address with public dns, still I had the same issue. Any idea, what is the best way to configure for EC2. Have gone through the link https://docs.google.com/document/d/175duUNIx7m5mCDa2sjXVI04ekyMa5bdiWdu-AFgisaY/edit?hl=en But not sure whether it's fixed in 1.1.4. When I run the nodetool ring, it gives the private ips. But in the above doc, it shows the public IPs as part of nodetool ring. Some insight into this is really helpful. Thanks Santi
Re: bug with cqlsh for foreign charater
Can you please put together a test case using CQL 3 to write and read the data and create a ticket at https://issues.apache.org/jira/browse/CASSANDRA ? Thanks Aaron - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 12/12/2012, at 11:12 AM, Wei Zhu wz1...@yahoo.com wrote: I have a column family with composite column CompositeType(UTF8Type, UTF8Type, LongType, UTF8Type) It stores (firstName, LastName, userID, meaningfulColumnName), if I insert the record with foreign characters, looks like that cqlsh -3 interprets the values wrong. I can get the values back from Hector correctly. Look at the highlighted row, the column2 and column3 are reversed. cqlsh:XXX select * from YY where key = 1; key | column1 | column2 | column3 | column4 | value ---+---+---+---+-+ 1 | | friendlname4 | 10004 | v | 333030303034403440304030402d404040667269656e646c6e616d6534 1 | afriendfname2 | afriendlname2 | 10002 | v | 3330303030324032403040304061667269656e64666e616d65322d40404061667269656e646c6e616d6532 1 | friendfname1 | | 10001 | v | 33303030303140314030403040667269656e64666e616d65312d404040 1 | friendfname4 | friendlname4 | 10004 | v | 33303030303440344030403040667269656e64666e616d65342d404040667269656e646c6e616d6534 1 |中国人 | صباح الخير | 10003 | v | 33303030303340334030403040e4b8ade59bbde4baba2d40404020d8b5d8a8d8a7d8ad20d8a7d984d8aed98ad8b120 Thanks. -Wei
Re: Multiple Data Center shows very uneven load
c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Address DC RackStatus State Load Effective-Ownership Token Token(bytes[6c03]) 11.111.111.1VA SVA Up Normal 1.44 GB 33.33% Token(bytes[6101]) 22.222.22.2 LA SLA Up Normal 361.25 MB 33.33% Token(bytes[6103]) 33.333.333.3VA SVA Up Normal 357.01 MB 33.33% Token(bytes[6601]) 44.444.44.4 LA SLA Up Normal 380.05 MB 33.33% Token(bytes[6603]) 55.555.555.5VA SNY Up Normal 498.43 MB 33.33% Token(bytes[6c01]) 66.666.666.6LA SNY Up Normal 512.21 MB 33.33% Token(bytes[6c03]) This already shows uneven load despite the fact that nodes actually hold the same amount of data (according to effective-ownership and application design / token values). Assuming you are using the Byte Ordered Partitioner. If so it's up to you to ensure your rows are evenly distributed between the nodes. Node 11.111.111.1 is responsible for a very wide range of tokens. I would suggest using the Random Partitioner unless you have a *very good* reason not to. I would go as far to say if you are using Cassandra for the firs time avoid the BOP until you have a better understanding of how Cassandra works. Why 11.111.111.1 still has 700+ MB of data? I tried nodetool repair, nodetool cleanup, and node restart (for 11.111.111.1) -- none of that helped (it still had those 700+ MB of data). Glancing at the logs it could be Hints or commit log replaying. Use nodetool cfstats to see which CF's are on the node and what their size is. If this is still a test the easiest thing to do is nuke it and start again. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 12/12/2012, at 12:23 PM, Sergey Olefir solf.li...@gmail.com wrote: aaron morton wrote Hi Sergey, I think you have forgotten to include some information in your email. Ah, I used Nable's markup and it seems to have eaten text somehow. Anyway, here it is without formatting (much harder to read though) I have a very similar issue myself and would love to know what (if anything) needs to be done (I'm using 1.1.6 at the moment). After stress-test (maximum load), I had the following on my nodes (every IP is changed to the corresponding fake number): c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Address DC RackStatus State Load Effective-Ownership Token Token(bytes[6c03]) 11.111.111.1VA SVA Up Normal 1.44 GB 33.33% Token(bytes[6101]) 22.222.22.2 LA SLA Up Normal 361.25 MB 33.33% Token(bytes[6103]) 33.333.333.3VA SVA Up Normal 357.01 MB 33.33% Token(bytes[6601]) 44.444.44.4 LA SLA Up Normal 380.05 MB 33.33% Token(bytes[6603]) 55.555.555.5VA SNY Up Normal 498.43 MB 33.33% Token(bytes[6c01]) 66.666.666.6LA SNY Up Normal 512.21 MB 33.33% Token(bytes[6c03]) This already shows uneven load despite the fact that nodes actually hold the same amount of data (according to effective-ownership and application design / token values). However I then proceeded to drop the single keyspace that was on this cluster and I got this: c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Note: Ownership information does not include topology, please specify a keyspace. Address DC RackStatus State LoadOwns Token Token(bytes[6c03]) 11.111.111.1VA SVA Up Normal 767.16 MB 16.67% Token(bytes[6101]) 22.222.22.2 LA SLA Up Normal 35.19 KB 16.67% Token(bytes[6103]) 33.333.333.3VA SVA Up Normal 52.91 KB 16.67% Token(bytes[6601]) 44.444.44.4 LA SLA Up Normal 50.09 KB 16.67% Token(bytes[6603]) 55.555.555.5VA SNY Up Normal 50.12 KB 16.67% Token(bytes[6c01]) 66.666.666.6LA SNY Up Normal 44.23 KB 16.67% Token(bytes[6c03]) Why 11.111.111.1 still has 700+ MB of data? I tried nodetool repair, nodetool cleanup, and node restart (for 11.111.111.1) -- none of that helped (it still had those 700+ MB of data). Here's info from the filesystem on that node:
Re: Consistency QUORUM does not work anymore (hector:Could not fullfill request on this host)
sliceRangeQuery.setRange(Character.Min_Value, Character.Max_Value, false,
Integer.Max_Value);
Try selecting a smaller number of rows.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
-
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 12/12/2012, at 8:12 PM, dong.yajun dongt...@gmail.com wrote:
hi aaron.
There is no problem with get_slices but get_range_slices failed. the way I
use this method is:
sliceRangeQuery.setFamily(family);
sliceRangeQuery.setKeys(rowkey,rowkey);
sliceRangeQuery.setRange(Character.Min_Value, Character.Max_Value, false,
Integer.Max_Value);
sliceRangeQuery.setRowCount(1);
current family has only abort 1 rows, each row has ~10columns, the data
abort 25k.
On Wed, Dec 12, 2012 at 11:13 AM, dong.yajun dongt...@gmail.com wrote:
Thanks aaron.
more information is I can read data correctly using Aqulies with
Local_Quorum.
I just check the system.log which is normal on 172.16.74.31 and the number of
RPC time out is 10s. the client exception occured on 2012-12-05.
and the all log on server on 2012-12-05 were:
WARN [pool-1-thread-1] 2012-12-05 11:17:10,974 Memtable.java (line 169)
setting live ratio to minimum of 1.0 instead of 0.09080883864721297
INFO [pool-1-thread-1] 2012-12-05 11:17:10,974 Memtable.java (line 179)
CFS(Keyspace='APIPortal', ColumnFamily='Log') liveRatio is 1.0 (just-counted
was 1.0). calculation took 4ms for 256 columns
INFO [pool-1-thread-1] 2012-12-05 17:48:25,988 Memtable.java (line 179)
CFS(Keyspace='APIPortal', ColumnFamily='WebSite') liveRatio is
2.780009341429239 (just-counted was 2.780009341429239). calculation took 1ms
for 52 columns
INFO [pool-1-thread-1] 2012-12-05 17:48:27,944 Memtable.java (line 179)
CFS(Keyspace='APIPortal', ColumnFamily='WebSite') liveRatio is
2.780009341429239 (just-counted was 2.3128462147190714). calculation took
1ms for 75 columns
INFO [CompactionExecutor:153] 2012-12-05 18:11:27,718 AutoSavingCache.java
(line 269) Saved OpsCenter-rollups60-KeyCache (18 items) in 2 ms
INFO [COMMIT-LOG-WRITER] 2012-12-05 20:31:10,025 CommitLogSegment.java (line
60) Creating new commitlog segment
/data/cassandra/commitlog/CommitLog-1354768270025.log
INFO [ScheduledTasks:1] 2012-12-05 21:47:38,352 GCInspector.java (line 123)
GC for ParNew: 437 ms for 1 collections, 1163185072 used; max is 8375238656
INFO [CompactionExecutor:163] 2012-12-05 22:11:27,679 AutoSavingCache.java
(line 269) Saved APIPortal-WebSite-KeyCache (1 items) in 2 ms
On Wed, Dec 12, 2012 at 5:45 AM, aaron morton aa...@thelastpickle.com wrote:
Caused by: TimedOutException()
Means the nodes involved in the request did not return to the co ordinator
before the rpc_timeout expired.
Check the logs on the servers to see if they are overloaded and dropping
messages.
Also check that you are not asking for too much data.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 11/12/2012, at 10:13 PM, dong.yajun dongt...@gmail.com wrote:
hi list,
I am using Cassandra with 3 data centers, each DC has more than 10 nodes.
the schema for a keyspace:
{DC1:3, DC2:3, DC3:3}
now, I put some rows using hector with CL Local_Quorum in DC1 ，and then I
get a row with the same CL Local_Quorum in DC1，some exceptions were occured:
Cassandra with dsc-1.0.5, and Hector with 1.1-2.
2012-12-05 21:26:49,667 - WARN [pool-1-thread-3:JCLLoggerAdapter@379] -
Could not fullfill request on this host CassandraClient172.16.74.31:9160-1
2012-12-05 21:26:49,668 - WARN [pool-1-thread-3:JCLLoggerAdapter@437] -
Exception:
me.prettyprint.hector.api.exceptions.HTimedOutException: TimedOutException()
at
me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:35)
at
me.prettyprint.cassandra.service.KeyspaceServiceImpl$3.execute(KeyspaceServiceImpl.java:163)
at
me.prettyprint.cassandra.service.KeyspaceServiceImpl$3.execute(KeyspaceServiceImpl.java:145)
at
me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:103)
at
me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:258)
at
me.prettyprint.cassandra.service.KeyspaceServiceImpl.operateWithFailover(KeyspaceServiceImpl.java:131)
at
me.prettyprint.cassandra.service.KeyspaceServiceImpl.getRangeSlices(KeyspaceServiceImpl.java:167)
at
me.prettyprint.cassandra.model.thrift.ThriftRangeSlicesQuery$1.doInKeyspace(ThriftRangeSlicesQuery.java:66)
at
me.prettyprint.cassandra.model.thrift.ThriftRangeSlicesQuery$1.doInKeyspace(ThriftRangeSlicesQuery.java:62)
at
Re: Multiple Data Center shows very uneven load
I do have a (good?) reason for ByteOrderedPartitioner - I need to be able to do range queries. At the same time I'm aware of the need to balance the cluster - so I'm hashing my keys and prefixing them with latin letters from a to p (16 in total) - hence the tokens I'm using. Based on my experiments I also think that effective ownership as reported by nodetool is accurate - so it seems this cluster is perfectly balanced. What I'm worrying about here is the fact that the load on the cluster is very uneven even after a short test and it doesn't get better when cluster is idle. Even more worryingly it doesn't fix itself after I dropped the only keyspace that was ever on this cluster. So I'm afraid that some data is getting orphaned - and it could become a real problem in production. I'd love some kind of confirmation one way or another - is this something I need to worry about or will it fix itself somehow over time? P.S. I actually had a repeat performance under another test - hugely uneven data load and data that won't go away even after keyspace drop. aaron morton wrote c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Address DC RackStatus State Load Effective-Ownership Token Token(bytes[6c03]) 11.111.111.1VA SVA Up Normal 1.44 GB 33.33% Token(bytes[6101]) 22.222.22.2 LA SLA Up Normal 361.25 MB 33.33% Token(bytes[6103]) 33.333.333.3VA SVA Up Normal 357.01 MB 33.33% Token(bytes[6601]) 44.444.44.4 LA SLA Up Normal 380.05 MB 33.33% Token(bytes[6603]) 55.555.555.5VA SNY Up Normal 498.43 MB 33.33% Token(bytes[6c01]) 66.666.666.6LA SNY Up Normal 512.21 MB 33.33% Token(bytes[6c03]) This already shows uneven load despite the fact that nodes actually hold the same amount of data (according to effective-ownership and application design / token values). Assuming you are using the Byte Ordered Partitioner. If so it's up to you to ensure your rows are evenly distributed between the nodes. Node 11.111.111.1 is responsible for a very wide range of tokens. I would suggest using the Random Partitioner unless you have a *very good* reason not to. I would go as far to say if you are using Cassandra for the firs time avoid the BOP until you have a better understanding of how Cassandra works. Why 11.111.111.1 still has 700+ MB of data? I tried nodetool repair, nodetool cleanup, and node restart (for 11.111.111.1) -- none of that helped (it still had those 700+ MB of data). Glancing at the logs it could be Hints or commit log replaying. Use nodetool cfstats to see which CF's are on the node and what their size is. If this is still a test the easiest thing to do is nuke it and start again. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 12/12/2012, at 12:23 PM, Sergey Olefir lt; solf.lists@ gt; wrote: aaron morton wrote Hi Sergey, I think you have forgotten to include some information in your email. Ah, I used Nable's markup and it seems to have eaten text somehow. Anyway, here it is without formatting (much harder to read though) I have a very similar issue myself and would love to know what (if anything) needs to be done (I'm using 1.1.6 at the moment). After stress-test (maximum load), I had the following on my nodes (every IP is changed to the corresponding fake number): c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Address DC RackStatus State Load Effective-Ownership Token Token(bytes[6c03]) 11.111.111.1VA SVA Up Normal 1.44 GB 33.33% Token(bytes[6101]) 22.222.22.2 LA SLA Up Normal 361.25 MB 33.33% Token(bytes[6103]) 33.333.333.3VA SVA Up Normal 357.01 MB 33.33% Token(bytes[6601]) 44.444.44.4 LA SLA Up Normal 380.05 MB 33.33% Token(bytes[6603]) 55.555.555.5VA SNY Up Normal 498.43 MB 33.33% Token(bytes[6c01]) 66.666.666.6LA SNY Up Normal 512.21 MB 33.33% Token(bytes[6c03]) This already shows uneven load despite the fact that nodes actually hold the same amount of data (according to effective-ownership and application design / token values). However I then proceeded to drop the single keyspace that was on this cluster and I got this: c:\SERVERS\apache-cassandra-1.1.6\binnodetool -h 11.111.111.1 ring Starting NodeTool Note:
Re: Multiple Data Center shows very uneven load
Nick Bailey-2 wrote Dropping a keyspace causes a snapshot to be taken of the keyspace before it is removed from the schema. So it won't actually delete any data. You can manually delete the data from /var/lib/cassandra/ ks /lt;cf[s]gt;/snapshots Indeed, it looks like snapshot is on the file system. However it looks like it is not the only thing by a long shot, i.e.: cassa1-1:/var/log/cassandra# du -k /spool1/cassandra/data/1.1/ 375372 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily/snapshots/1355222054452-marquisColumnFamily 375376 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily/snapshots 375380 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily 375384 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace 4 /spool1/cassandra/data/1.1/system/Versions 52 /spool1/cassandra/data/1.1/system/schema_columns 4 /spool1/cassandra/data/1.1/system/Schema 28 /spool1/cassandra/data/1.1/system/NodeIdInfo 4 /spool1/cassandra/data/1.1/system/Migrations 28 /spool1/cassandra/data/1.1/system/schema_keyspaces 28 /spool1/cassandra/data/1.1/system/schema_columnfamilies 786348 /spool1/cassandra/data/1.1/system/HintsColumnFamily 52 /spool1/cassandra/data/1.1/system/LocationInfo 4 /spool1/cassandra/data/1.1/system/IndexInfo 786556 /spool1/cassandra/data/1.1/system 1161944 /spool1/cassandra/data/1.1/ And also 700+MB in the commitlog. Neither of which seemed to 'go away' on its own when idle or even after running nodetool repair/cleanup and even dropping keyspace. I suppose these hints and commitlog may be the reason behind huge difference in load on nodes -- but why does it happen and more importantly is it harmful? Will it keep accumulating? -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Multiple-Data-Center-shows-very-uneven-load-tp7584197p7584256.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.
Re: Null Error Running pig_cassandra
there is about 3 checks that should have caught the Null. at org.apache.cassandra.hadoop.ConfigHelper.getInputSlicePredicate(ConfigHelper.java:176) This line does not match the source code for the 1.2.0-beta3 tag. Can you try it with the 1.1.7 bin distro ? Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 13/12/2012, at 6:04 AM, James Schappet jschap...@gmail.com wrote: When trying to run the example-script.pig, I get the following error, null error. tsunami:pig schappetj$ bin/pig_cassandra -x local example-script.pig Using /Library/pig-0.10.0/pig-0.10.0.jar. 2012-12-12 11:02:54,079 [main] INFO org.apache.pig.Main - Apache Pig version 0.10.0 (r1328203) compiled Apr 20 2012, 00:33:25 2012-12-12 11:02:54,079 [main] INFO org.apache.pig.Main - Logging error messages to: /Library/apache-cassandra-1.2.0-beta3-src/examples/pig/pig_1355331774074.log 2012-12-12 11:02:54.211 java[78283:1c03] Unable to load realm info from SCDynamicStore 2012-12-12 11:02:54,400 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:/// 2012-12-12 11:02:54,890 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1200: null Details at logfile: /Library/apache-cassandra-1.2.0-beta3-src/examples/pig/pig_1355331774074.log PIG 0.10.0 Cassandra 1.2.0-Beta3 w/source ENV Osx Lion: $ java -version java version 1.7.0_04 Java(TM) SE Runtime Environment (build 1.7.0_04-b21) Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode) set | grep PIG PIG_HOME=/Library/pig-0.10.0 PIG_INITIAL_ADDRESS=localhost PIG_PARTITIONER=org.apache.cassandra.dht.RandomPartitioner PIG_RPC_PORT=9160 Pig Stack Trace --- ERROR 1200: null org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1000: Error during parsing. null at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1597) at org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:1540) at org.apache.pig.PigServer.registerQuery(PigServer.java:540) at org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:970) at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:386) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:189) at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:165) at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84) at org.apache.pig.Main.run(Main.java:555) at org.apache.pig.Main.main(Main.java:111) 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:601) at org.apache.hadoop.util.RunJar.main(RunJar.java:156) Caused by: Failed to parse: null at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:184) at org.apache.pig.PigServer$Graph.parseQuery(PigServer.java:1589) ... 14 more Caused by: java.lang.NullPointerException at org.apache.cassandra.utils.Hex.hexToBytes(Hex.java:51) at org.apache.cassandra.hadoop.ConfigHelper.predicateFromString(ConfigHelper.java:206) at org.apache.cassandra.hadoop.ConfigHelper.getInputSlicePredicate(ConfigHelper.java:176) at org.apache.cassandra.hadoop.pig.CassandraStorage.setLocation(CassandraStorage.java:577) at org.apache.cassandra.hadoop.pig.CassandraStorage.getSchema(CassandraStorage.java:610) at org.apache.pig.newplan.logical.relational.LOLoad.getSchemaFromMetaData(LOLoad.java:151) at org.apache.pig.newplan.logical.relational.LOLoad.getSchema(LOLoad.java:110) at org.apache.pig.parser.LogicalPlanGenerator.alias_col_ref(LogicalPlanGenerator.java:15356) at org.apache.pig.parser.LogicalPlanGenerator.col_ref(LogicalPlanGenerator.java:15203) at org.apache.pig.parser.LogicalPlanGenerator.projectable_expr(LogicalPlanGenerator.java:8881) at org.apache.pig.parser.LogicalPlanGenerator.var_expr(LogicalPlanGenerator.java:8632) at org.apache.pig.parser.LogicalPlanGenerator.expr(LogicalPlanGenerator.java:7984) at org.apache.pig.parser.LogicalPlanGenerator.flatten_clause(LogicalPlanGenerator.java:6103) at org.apache.pig.parser.LogicalPlanGenerator.flatten_generated_item(LogicalPlanGenerator.java:5926) at org.apache.pig.parser.LogicalPlanGenerator.generate_clause(LogicalPlanGenerator.java:14101) at org.apache.pig.parser.LogicalPlanGenerator.foreach_plan(LogicalPlanGenerator.java:12493) at
Re: upgrade from 0.8.5 to 1.1.6, now it cannot find schema
in-vm cassandra Embedded ? The location of the SSTables has changed in 1.1, they are know in /var/lib/cassandra/data/KS_NAME/CF_NAME/SSTable.data Is the data in the right place ? Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 13/12/2012, at 6:54 AM, Anand Somani meatfor...@gmail.com wrote: Hi, We have a service which uses in-vm cassandra and creates the schema if does not exist programmatically, this has worked for us for sometime (including upgrades to the service) and we have been using 0.8.5. Now we are testing the upgrade to 1.1.6 and noticed that on upgrade the cassandra fails to find the old schema and wants to create a schema!!. Even using cli it does not show the old schema. Has anybody come across this? FYI we have another cluster where we run cassandra as a separate process and schema is also created outside using cli, the upgrade there went fine!! Has anybody seen this behavior? Any clues? I am going to look at creating the schema from outside, so see if that is culprit but wanted to see if anybody had any suggestions/thoughts. Thanks Anand
Re: Multiple Data Center shows very uneven load
try nodetool drain. It will flush everything to disk and the commit log will be truncated. HH can be ignored. If you really want them gone they can be purged using the JMX interface, or you can stop the node and delete the sstables. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 13/12/2012, at 10:35 AM, Sergey Olefir solf.li...@gmail.com wrote: Nick Bailey-2 wrote Dropping a keyspace causes a snapshot to be taken of the keyspace before it is removed from the schema. So it won't actually delete any data. You can manually delete the data from /var/lib/cassandra/ ks /lt;cf[s]gt;/snapshots Indeed, it looks like snapshot is on the file system. However it looks like it is not the only thing by a long shot, i.e.: cassa1-1:/var/log/cassandra# du -k /spool1/cassandra/data/1.1/ 375372 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily/snapshots/1355222054452-marquisColumnFamily 375376 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily/snapshots 375380 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace/marquisColumnFamily 375384 /spool1/cassandra/data/1.1/rainmanLoadTestKeyspace 4 /spool1/cassandra/data/1.1/system/Versions 52 /spool1/cassandra/data/1.1/system/schema_columns 4 /spool1/cassandra/data/1.1/system/Schema 28 /spool1/cassandra/data/1.1/system/NodeIdInfo 4 /spool1/cassandra/data/1.1/system/Migrations 28 /spool1/cassandra/data/1.1/system/schema_keyspaces 28 /spool1/cassandra/data/1.1/system/schema_columnfamilies 786348 /spool1/cassandra/data/1.1/system/HintsColumnFamily 52 /spool1/cassandra/data/1.1/system/LocationInfo 4 /spool1/cassandra/data/1.1/system/IndexInfo 786556 /spool1/cassandra/data/1.1/system 1161944 /spool1/cassandra/data/1.1/ And also 700+MB in the commitlog. Neither of which seemed to 'go away' on its own when idle or even after running nodetool repair/cleanup and even dropping keyspace. I suppose these hints and commitlog may be the reason behind huge difference in load on nodes -- but why does it happen and more importantly is it harmful? Will it keep accumulating? -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Multiple-Data-Center-shows-very-uneven-load-tp7584197p7584256.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.
Datastax C*ollege Credit Webinar Series : Create your first Java App w/ Cassandra
FWIW -- I'm presenting tomorrow for the Datastax C*ollege Credit Webinar Series: http://brianoneill.blogspot.com/2012/12/presenting-for-datastax-college-credit.html I hope to make CQL part of the presentation and show how it integrates with the Java APIs. If you are interested, drop in. -brian -- Brian ONeill Lead Architect, Health Market Science (http://healthmarketscience.com) mobile:215.588.6024 blog: http://brianoneill.blogspot.com/ twitter: @boneill42
Re: Why Secondary indexes is so slowly by my test?
You are right, Dean. It's due to the heavy result returned by query, not index
itself. According to my test, if the result rows less than 5000, it's very
quick. But how to limit the result? It seems row limit is a good choice. But if
do so, some rows I wanted maybe miss because the row order not fulfill query
conditions.
For example: CF User{I1,C1} with Index I1. Query conditions:I1=foo, order by
C1. If I1=foo return 1 limit 100, I can't get the right result of C1. Also
we can not always set row range fulfill the query conditions when doing query.
Maybe I should redesign the CF model to fix it.
-- Original --
From: Hiller, Deandean.hil...@nrel.gov;
Date: Wed, Dec 12, 2012 10:51 PM
To: user@cassandra.apache.orguser@cassandra.apache.org;
Subject: Re: Why Secondary indexes is so slowly by my test?
You could always try PlayOrm's query capability on top of cassandra ;)??.it
works for us.
Dean
From: Chengying Fang cyf...@ngnsoft.commailto:cyf...@ngnsoft.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, December 11, 2012 8:22 PM
To: user user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: Why Secondary indexes is so slowly by my test?
Thanks to Low. We use CompositeColumn to substitue it in single not-equality
and definite equalitys query. And we will give up cassandra because of the weak
query ability and unstability. Many times, we found our data in confusion
without definite cause in our cluster. For example, only two rows in one CF,
row1-columnname1-columnvalue1,row2-columnname2-columnvalue2, but some times, it
becomes row1-columnname1-columnvalue2,row2-columnname2-columnvalue1. Notice the
wrong column value.
-- Original --
From: Richard Lowr...@acunu.commailto:r...@acunu.com;
Date: Tue, Dec 11, 2012 07:44 PM
To: useruser@cassandra.apache.orgmailto:user@cassandra.apache.org;
Subject: Re: Why Secondary indexes is so slowly by my test?
Hi,
Secondary index lookups are more complicated than normal queries so will be
slower. Items have to first be queried in the index, then retrieved from their
actual location. Also, inserting into indexed CFs will be slower (but will get
substantially faster in 1.2 due to CASSANDRA-2897).
If you need to retrieve large amounts of data with your query, you would be
better off changing your data model to not use secondary indexes.
Richard.
On 7 December 2012 03:08, Chengying Fang
cyf...@ngnsoft.commailto:cyf...@ngnsoft.com wrote:
Hi guys,
I found Secondary indexes too slowly in my product(amazon large instance) with
cassandra, then I did test again as describe here. But the result is the same
as product. What's wrong with cassandra or me?
Now my test:
newly installed ubuntu-12.04 LTS , apache-cassandra-1.1.6, default configure,
just one keyspace(test) and one CF(TestIndex):
1. CREATECOLUMN FAMILY TestIndex
2. WITH comparator = UTF8Type
3. AND key_validation_class=UTF8Type
4. AND default_validation_class = UTF8Type
5. AND column_metadata = [
6. {column_name: tk, validation_class: UTF8Type, index_type: KEYS}
7. {column_name: from, validation_class: UTF8Type}
8. {column_name: to, validation_class: UTF8Type}
9. {column_name: tm, validation_class: UTF8Type}
10. ];
and 'tk' just three value:'A'(1000row),'B'(1000row),'X'(increment by test)
The test query from cql:
1,without index:selectcount(*) from TestIndex limit 100;
2,with index:selectcount(*) from TestIndex where tk='X' limit 100;
When I insert 6 row 'X', the time:1s and 12s.
When 'X' up to 13,the time:2.3s and 33s.
When 'X' up to 25,the time:3.8s and 53s.
According to this, when 'X' up to billon, what's the result? Can Secondary
indexes be used in product? I hope it's my mistake in doing this test.Can
anyone give some tips about it?
Thanks in advance.
fancy
--
Richard Low
Acunu | http://www.acunu.com | @acunu
Re: Why Secondary indexes is so slowly by my test?
The IndexClause for the get_indexed_slices takes a start key. You can page the
results from your secondary index query by making multiple calls with a sane
count and including a start key.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 13/12/2012, at 6:34 PM, Chengying Fang cyf...@ngnsoft.com wrote:
You are right, Dean. It's due to the heavy result returned by query, not
index itself. According to my test, if the result rows less than 5000, it's
very quick. But how to limit the result? It seems row limit is a good choice.
But if do so, some rows I wanted maybe miss because the row order not
fulfill query conditions.
For example: CF User{I1,C1} with Index I1. Query conditions:I1=foo, order by
C1. If I1=foo return 1 limit 100, I can't get the right result of C1.
Also we can not always set row range fulfill the query conditions when doing
query. Maybe I should redesign the CF model to fix it.
-- Original --
From: Hiller, Deandean.hil...@nrel.gov;
Date: Wed, Dec 12, 2012 10:51 PM
To: user@cassandra.apache.orguser@cassandra.apache.org;
Subject: Re: Why Secondary indexes is so slowly by my test?
You could always try PlayOrm's query capability on top of cassandra ;)??.it
works for us.
Dean
From: Chengying Fang cyf...@ngnsoft.commailto:cyf...@ngnsoft.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, December 11, 2012 8:22 PM
To: user user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: Why Secondary indexes is so slowly by my test?
Thanks to Low. We use CompositeColumn to substitue it in single not-equality
and definite equalitys query. And we will give up cassandra because of the
weak query ability and unstability. Many times, we found our data in
confusion without definite cause in our cluster. For example, only two rows
in one CF, row1-columnname1-columnvalue1,row2-columnname2-columnvalue2, but
some times, it becomes
row1-columnname1-columnvalue2,row2-columnname2-columnvalue1. Notice the wrong
column value.
-- Original --
From: Richard Lowr...@acunu.commailto:r...@acunu.com;
Date: Tue, Dec 11, 2012 07:44 PM
To: useruser@cassandra.apache.orgmailto:user@cassandra.apache.org;
Subject: Re: Why Secondary indexes is so slowly by my test?
Hi,
Secondary index lookups are more complicated than normal queries so will be
slower. Items have to first be queried in the index, then retrieved from
their actual location. Also, inserting into indexed CFs will be slower (but
will get substantially faster in 1.2 due to CASSANDRA-2897).
If you need to retrieve large amounts of data with your query, you would be
better off changing your data model to not use secondary indexes.
Richard.
On 7 December 2012 03:08, Chengying Fang
cyf...@ngnsoft.commailto:cyf...@ngnsoft.com wrote:
Hi guys,
I found Secondary indexes too slowly in my product(amazon large instance)
with cassandra, then I did test again as describe here. But the result is the
same as product. What's wrong with cassandra or me?
Now my test:
newly installed ubuntu-12.04 LTS , apache-cassandra-1.1.6, default configure,
just one keyspace(test) and one CF(TestIndex):
1. CREATECOLUMN FAMILY TestIndex
2. WITH comparator = UTF8Type
3. AND key_validation_class=UTF8Type
4. AND default_validation_class = UTF8Type
5. AND column_metadata = [
6. {column_name: tk, validation_class: UTF8Type, index_type: KEYS}
7. {column_name: from, validation_class: UTF8Type}
8. {column_name: to, validation_class: UTF8Type}
9. {column_name: tm, validation_class: UTF8Type}
10. ];
and 'tk' just three value:'A'(1000row),'B'(1000row),'X'(increment by test)
The test query from cql:
1,without index:selectcount(*) from TestIndex limit 100;
2,with index:selectcount(*) from TestIndex where tk='X' limit 100;
When I insert 6 row 'X', the time:1s and 12s.
When 'X' up to 13,the time:2.3s and 33s.
When 'X' up to 25,the time:3.8s and 53s.
According to this, when 'X' up to billon, what's the result? Can Secondary
indexes be used in product? I hope it's my mistake in doing this test.Can
anyone give some tips about it?
Thanks in advance.
fancy
--
Richard Low
Acunu | http://www.acunu.com | @acunu
