system.NodeIdInfo - leftover from Cassandra 0.8.3 ?
I've half inherited Cassandra administration on a two DC cluster with 8 nodes (4 in each DC). We've just successfully completed the upgrade to 2.1.6 On completion of upgradesstables the only remaining "jb" sstable was in the System keyspace for NodeIdInfo. I notice that this is no longer included in the schema. I presume the NodeIdInfo sstable can be safely delete. Is this a safe presumption? Thanks .BN
Re: Hector Problem Basic one
Thanks for the reply ben. Actually The problem is, I could not able to run a basic hector example from eclipse. Its throwing me.prettyprint.hector.api. exceptions.HectorException: All host pools marked down. Retry burden pushed out to client Can you please let me know why i am getting this On Tue, Oct 11, 2011 at 3:54 PM, Ben Ashton b...@bossastudios.com wrote: Hey, We had this one, even tho in the hector documentation it says that it retry s failed servers even 30 by default, it doesn't. Once we explicitly set it to X seconds, when ever there is a failure, ie with network (AWS), it will retry and add it back into the pool. Ben On 11 October 2011 11:09, CASSANDRA learner cassandralear...@gmail.com wrote: Hi Every One, Actually I was using cassandra long time back and when i tried today, I am getting a problem from eclipse. When i am trying to run a basic hector (java) example, I am getting an exception me.prettyprint.hector.api.exceptions.HectorException: All host pools marked down. Retry burden pushed out to client. . But My server is up. Node tool also whows that it is up. I donno what happens.. 1.)Is it any thing to do with JMX port. 2.) What is the storage port in casandra.yaml and jmx port in cassandra-env.sh
Hector Problem Basic one
Hi Every One, Actually I was using cassandra long time back and when i tried today, I am getting a problem from eclipse. When i am trying to run a basic hector (java) example, I am getting an exception me.prettyprint.hector.api.exceptions.HectorException: All host pools marked down. Retry burden pushed out to client. . But My server is up. Node tool also whows that it is up. I donno what happens.. 1.)Is it any thing to do with JMX port. 2.) What is the storage port in casandra.yaml and jmx port in cassandra-env.sh
Re: HOW TO select a column or all columns that start with X
Can you please gimme an example on this using hector client On Thu, Aug 4, 2011 at 7:18 AM, Boris Yen yulin...@gmail.com wrote: It seems to me that your column name consists of two components. If you have the luxury to upgrade your cassandra to 0.8.1+, I think you can think about using the composite type/column. Conceptually, it might suit your use case better. On Wed, Aug 3, 2011 at 5:28 AM, Eldad Yamin elda...@gmail.com wrote: Hello, I wonder if I can select a column or all columns that start with X. E.g I have columns ABC_1, ABC_2, ZZZ_1 and I want to select all columns that start with ABC_ - is that possible? Thanks!
Sample Cassandra project in Tomcat
Hiii, Can any one pleaze send me any sample application which is (.war) implemented in java/jsp and cassandra db (Tomcat)
Killing cassandra is not working
H,, I was running cassandra in my mac and after some time the machine got to sleep mode. Now after the machine is On. I tried to kill the process of cassandra. But i could not able to do that as i could not able to find out the process id. theres no process there when i pinged PS command in mac os. I though its already killed and i have tried to start cassandra by typing bin/cassandra. I got the below error (in red color) due to the same. ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510) JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports initialized [../../../src/share/back/debugInit.c:690] FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197) Can you please resolve this issue. Thnkx in Adv[?] 330.gif
Re: Killing cassandra is not working
Thnks for the reply Nila When i did PS command, I could not able to find any process related to cassandra. Thts the problem.. On Wed, Aug 3, 2011 at 4:12 PM, Benoit Perroud ben...@noisette.ch wrote: Seems like you have already a Cassandra instance running, so the second instance cannot open the same port twice. I would suggest you to kill all instances of Cassandra and start it again. 2011/8/3 Nilabja Banerjee nilabja.baner...@gmail.com try to use *grep* command to check the port where your cassandra was running. On 3 August 2011 16:01, CASSANDRA learner cassandralear...@gmail.comwrote: H,, I was running cassandra in my mac and after some time the machine got to sleep mode. Now after the machine is On. I tried to kill the process of cassandra. But i could not able to do that as i could not able to find out the process id. theres no process there when i pinged PS command in mac os. I though its already killed and i have tried to start cassandra by typing bin/cassandra. I got the below error (in red color) due to the same. ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510) JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports initialized [../../../src/share/back/debugInit.c:690] FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197) Can you please resolve this issue. Thnkx in Adv[?] 330.gif
Re: Sample Cassandra project in Tomcat
Hi, Thnks for the info On Wed, Aug 3, 2011 at 4:03 PM, samal sa...@wakya.in wrote: I don't know much about this, may help you.. http://www.codefreun.de/apolloUI/ http://www.codefreun.de/apollo/ On Wed, Aug 3, 2011 at 3:36 PM, CASSANDRA learner cassandralear...@gmail.com wrote: Hiii, Can any one pleaze send me any sample application which is (.war) implemented in java/jsp and cassandra db (Tomcat)
Significance of java_pidxxx.hprof
As per subject, Please explain me what is the significance of java_pidxxx.hprof
Re: Slow Reads
R u using hector client for java
On Tue, Jul 26, 2011 at 11:17 PM, Priyanka priya...@gmail.com wrote:
this is how my data looks
“rowkey1”:{
“supercol1”:{ “col1”:T,”col2”:C}
“supercol2”:{“col1”:C,”col2”:T }
“supercol3”:{ “col1”:C,”col2”:T}
}
rowkey2”:{
“supercol1”:{ “col1”:A,”col2”:A}
“supercol2”:{“col1”:A,”col2”:T }
“supercol3”:{ “col1”:C,”col2”:T}
}
each row has 620901 super columns and 2 columns for each super column.
Name of the super columns remain same for all the rows but the data in each
super column is different.
I am trying to get the data of a particular super col which is spread
across
all the rows but with different data.
So yes,its getting data from all rows.
Please suggest me a better way to do so.
Thank you.
the output of my query will be (suppose if i do for supercol1)
rowkey1,T,C
rowkey2,A,A
--
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Is Cassandra Secured
Hi, My Question is regarding security. The data will be written in the disks in strings right! then how come the data is secured, Is it not secured ???
Can we store java objects and images/files in cassandra
Hi, Can we store images , java objects, files in cassandra, if so , how Please let me know this as i need it urgently...
Read process
Hi, I am having one doubt regarding reads. The data will be stored in commitlog,memtable,sstables right.. While reading the data may be available in all the three right, then from where the reads happens,, form commit log? or from Memtable ? or from SSTables.. Please explain friends Thnks
Re: Can we store java objects and images/files in cassandra
Thanks for the response Oliver, Can you please let me know where can i find an example for storing images and files. I could not able to find one in tht link. Please let me know On Wed, Jul 27, 2011 at 1:48 PM, Oliver Dungey oliver.dun...@gmail.comwrote: You can store anything you like in Cassandra. The type of data is not relevant as there are no types in Cassandra, they all get stored as byte arrays. The only relevant limit is a column value cannot exceed 2GB (see http://wiki.apache.org/cassandra/CassandraLimitations). In terms of how: you just write the data like any other field. If you are new to NOSQL I would go and look at the Hector API and examples: https://github.com/rantav/hector
Re: Cassandra training in Bangalore, India
Yes Sure, That would be better if could make it out like fee kind or meetup some where some time... On Thu, Jul 21, 2011 at 11:35 AM, Sasha Dolgy sdo...@gmail.com wrote: I am quite certain if you find enough people and pony up the fees a few people on this list would be willing to make the journey... On Jul 21, 2011 8:02 AM, samal sa...@wakya.in wrote: As per my knowledge, there is not such expert training available in India as of now. As Sameer said there is enough online material available from where you can learn.I have been playing with Cassandra since beginning. We can plan for Meetup/learning session near Mumbai/Pune region.
Re: Memtables stored in which location
Hi, You r right but i too have some concerns... Any ways , some where memtable has to be stored right, like we say memtable data is flushed to create sstable on disk. Exactly from which location or memory it will be getting from. is it like an objects streams or like it is storing the values in commitlog. my next question is , data is written to commit log. all the data is available here, and the sstable are getting created on disk, then where and when these memtables are coming into picture On Thu, Jul 21, 2011 at 1:44 PM, samal sa...@wakya.in wrote: SSTable is stored on disk not memtable. Memtable is memory representation of data, which is on flush to create SSTable on disk. This is the location where SSTable is stored https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L71 Where as Commitlog which is back up (log) for memtable replaying store in https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L75 location. Once the all memtable is flushed to disk, new commit log segment is created. On Thu, Jul 21, 2011 at 1:12 PM, Abdul Haq Shaik abdulsk.cassan...@gmail.com wrote: Hi, Can you please let me know where exactly the memtables are getting stored. I wanted to know the physical location
Re: Memtables stored in which location
Thanks samal... I got it now On Thu, Jul 21, 2011 at 4:11 PM, samal sa...@wakya.in wrote: Any ways , some where memtable has to be stored right, like we say memtable data is flushed to create sstable on disk. Exactly from which location or memory it will be getting from. is it like an objects streams or like it is storing the values in commitlog. A Memtable is Cassandra's in-memory representation of key/value pairs. my next question is , data is written to commit log. all the data is available here, and the sstable are getting created on disk, then where and when these memtables are coming into picture Commitlog is append only file which record write sequentially, more[2], can be thought as check sum file, which to used to recalculate data for memtables in case of crash. A write first hits the *CommitLog*, then Cassandra stores/writes values to in-memory data structures called Memtables. The Memtables are flushed to disk whenever one of the configurable thresholds is met.[3] http://wiki.apache.org/cassandra/MemtableThresholds For each column family there is corresponding memtable. There is generally one commitlog file for all CF. SSTables are immutable once written to disk cannot be modified. It will only be replaced by new SSTable after compaction [1]http://wiki.apache.org/cassandra/ArchitectureOverview [2]http://wiki.apache.org/cassandra/ArchitectureCommitLog [3]http://wiki.apache.org/cassandra/MemtableThresholds
Re: Memtables stored in which location
Thanks Aaron and samal for your quick response. Its going to be helpful On Thu, Jul 21, 2011 at 4:15 PM, aaron morton aa...@thelastpickle.comwrote: Try the project wiki here http://wiki.apache.org/cassandra/ArchitectureOverview or the my own blog here http://thelastpickle.com/2011/04/28/Forces-of-Write-and-Read/ There is also a list of articles on the wiki here http://wiki.apache.org/cassandra/ArticlesAndPresentations in short, writes got to the commit log first, then the memtable in memory, which is later flushed to disk. A read is from potentially multiple sstables and memtables. Cheers - Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 21 Jul 2011, at 21:17, CASSANDRA learner wrote: Hi, You r right but i too have some concerns... Any ways , some where memtable has to be stored right, like we say memtable data is flushed to create sstable on disk. Exactly from which location or memory it will be getting from. is it like an objects streams or like it is storing the values in commitlog. my next question is , data is written to commit log. all the data is available here, and the sstable are getting created on disk, then where and when these memtables are coming into picture On Thu, Jul 21, 2011 at 1:44 PM, samal sa...@wakya.in wrote: SSTable is stored on disk not memtable. Memtable is memory representation of data, which is on flush to create SSTable on disk. This is the location where SSTable is stored https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L71 Where as Commitlog which is back up (log) for memtable replaying store in https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L75 location. Once the all memtable is flushed to disk, new commit log segment is created. On Thu, Jul 21, 2011 at 1:12 PM, Abdul Haq Shaik abdulsk.cassan...@gmail.com wrote: Hi, Can you please let me know where exactly the memtables are getting stored. I wanted to know the physical location
best example of indexing
Hi Guys, Can you please give me the best example of creating index on a column family. As I am completely new to this, Can you please give me a simple and good example.
Re: best example of indexing
where can i get that. Can you please help me out On Wed, Jul 20, 2011 at 3:39 PM, Sasha Dolgy sdo...@gmail.com wrote: Examples exist in the conf directory of the distribution... On Jul 20, 2011 11:48 AM, CASSANDRA learner cassandralear...@gmail.com wrote: Hi Guys, Can you please give me the best example of creating index on a column family. As I am completely new to this, Can you please give me a simple and good example.
Cassandra CLOUD . How its related
Hi Guys, When we talk about cassandra, any how we connect it to cloud. I dont understand how it is connected to cloud. Whats this Cassandra Cloud.
Cassandra 0.7 beta 3 outOfMemory (OOM)
Hi community, during my tests i had several OOM crashes. Getting some hints to find the problem would be nice. First cassandra crashes after about 45 min insert test script. During the following tests time to OOM was shorter until it started to crash even in idle mode. Here the facts: - cassandra 0.7 beta 3 - using lucandra to index about 3 million files ~1kb data - inserting with one client to one cassandra node with about 200 files/s - cassandra data files for this keyspace grow up to about 20 GB - the keyspace only contains the two lucandra specific CFs Cluster: - cassandra single node on windows 32bit, Xeon 2,5 Ghz, 4GB RAM - java jre 1.6.0_22 - heap space first 1GB, later increased to 1,3 GB Cassandra.yaml: default + reduced binary_memtable_throughput_in_mb to 128 CFs: default + reduced min_compaction_threshold: 4 max_compaction_threshold: 8 I think the problem appears always during compaction, and perhaps it is a result of large rows (some about 170mb). Are there more optionions we could use to work with few memory? Is it a problem of compaction? And how to avoid? Slower inserts? More memory? Even fewer memtable_throuput or in_memory_compaction_limit? Continuous manual major comapction? I've read http://www.riptano.com/docs/0.6/troubleshooting/index#nodes-are-dying-with-oom-errors - row_size should be fixed since 0.7 and 200mb is still far away from 2gb - only key cache is used a little bit 3600/2 - after a lot of writes cassandra crashes even in idle mode - memtablesize was reduced and there are only 2 CFs Several heapdumps in MAT show 60-99% heapusage of compaction thread. Here some log extract: INFO [CompactionExecutor:1] 2010-11-26 14:18:18,593 CompactionIterator.java (line 134) Compacting large row 6650325572717566efbfbf44545241434b53efbfbf31 (172967291 bytes) incrementally INFO [ScheduledTasks:1] 2010-11-26 14:18:41,421 GCInspector.java (line 133) GC for ParNew: 365 ms, 54551328 reclaimed leaving 459496840 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:42,437 GCInspector.java (line 133) GC for ParNew: 226 ms, 12469104 reclaimed leaving 554506776 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:43,453 GCInspector.java (line 133) GC for ParNew: 224 ms, 12777840 reclaimed leaving 649207976 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:44,468 GCInspector.java (line 133) GC for ParNew: 225 ms, 12564144 reclaimed leaving 744122872 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:45,468 GCInspector.java (line 133) GC for ParNew: 222 ms, 16020328 reclaimed leaving 835581584 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:46,468 GCInspector.java (line 133) GC for ParNew: 226 ms, 12697912 reclaimed leaving 930362712 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:47,468 GCInspector.java (line 133) GC for ParNew: 227 ms, 15816872 reclaimed leaving 1022026288 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:48,484 GCInspector.java (line 133) GC for ParNew: 258 ms, 12746584 reclaimed leaving 1116758744 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:49,484 GCInspector.java (line 133) GC for ParNew: 257 ms, 12802608 reclaimed leaving 1211435176 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 133) GC for ConcurrentMarkSweep: 4188 ms, 271308512 reclaimed leaving 1047605704 used; max is 1450442752 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 153) Pool NameActive Pending INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) ResponseStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) ReadStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) ReadRepair0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) MutationStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) GossipStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,546 GCInspector.java (line 160) AntientropyStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,562 GCInspector.java (line 160) MigrationStage0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,562 GCInspector.java (line 160) StreamStage 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,562 GCInspector.java (line 160) MemtablePostFlusher 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,562 GCInspector.java (line 160) FlushWriter 0 0 INFO [ScheduledTasks:1] 2010-11-26 14:18:54,562 GCInspector.java (line 160) MiscStage
