Bulk loading and timestamps

Hello, group Will the bulk loader preserve original column timestamps? Thank you very much, Oleg

Re: Bulkload into a different CF

Benoit Perroud benoit at noisette.ch writes: You can copy the sstables (renaming them accordingly) and call nodetool refresh. Thank you, Benoit. In that case could I try snapshot+moverename+refresh on a live system? Regards, Oleg

Re: Question regarding major compaction.

Henrik Schröder skrolle at gmail.com writes: But what's the difference between doing an extra read from that One Big File, than doing an extra read from whatever SSTable happen to be largest in the course of automatic minor compaction? There is this note regarding major compaction in the

Linux Filesystem for Cassandra

Hi, There has been no discussion on this list on the choice of a Linux file system for Cassandra. Does this choice make a difference? Would you, please share, what filesystem you are using? Thank you very much, Oleg

Quick advice needed - CF backup and restore

Hi, What is the easiest way to save/backup a single column family across the cluster and later reload it? Thank you very much, Oleg

Cassandra 0.8 CLI: Inconsistent treatment of literals for keys/columns and values

Hi, After installing Cassandra 0.8 I discovered that my app stopped working. The issue is that the app is now unable to read a row that was inserted by a CLI set command with a numeric string key. CLI in Cassandra 0.8 seems to be treating literals inconsistently. Please let me know if I am

Cassandra Thrift calls block indefinitely

Hi All, This is the first time I see this. I am using Hector for a bulk load into a 3 node Cassandra 0.7.0 cluster. I have been doing this for a while now but this time the load was more intense compared to the ones before and it was running from a single client machine because I was afraid to

Re: Unavalible Exception

ruslan usifov ruslan.usifov at gmail.com writes: HelloWhy i can get Unavalible Exception on live cluster (all nodes is up and never shutdown)PS: v 0.7.0 Can the nodes see each other? Check Cassandra logs for messages regarding other nodes. Oleg

Re: Unavalible Exception

ruslan usifov ruslan.usifov at gmail.com writes: 2011/2/4 Oleg Proudnikov olegp at cloudorange.com ruslan usifov ruslan.usifov at gmail.com writes: HelloWhy i can get Unavalible Exception on live cluster (all nodes is up andnever shutdown)PS: v 0.7.0 Can the nodes see each other? Check

CF Read and Write Latency Histograms

Hi All, I suspect that Write and Read Latency column headers need to be swapped. I am running a bulk load with no reads on this CF but I see Read column with values while the Write column has zeros only. The MBean shows the values correctly. Thank you, Oleg

Re: CF Read and Write Latency Histograms

David Dabbs dmdabbs at gmail.com writes: Is this 0.7? Yes

Re: How to monitor Cassandra's throughput?

The issue has been resolved, the fix is on Hector's GitHub. Oleg Proudnikov olegp at cloudorange.com writes: I have posted on Hector ML: http://thread.gmane.org/gmane.comp.db.hector.user/1690 Oleg

New Generation Size guidelines

Hi All, I have a 3 server cluster with RF=2. My heap is 2G out of a 4G RAM. The servers have 4 cores. I used default heap settings. The Eden space ended up around 60M and the Survivor spaces are around 7M. This feels a little bit low for a process that creates so much short-lived garbage. I just

Cassandra memory needs

Hi All, I am trying to understand the relationship between data set/SSTable(s) size and Cassandra heap. Q1. Here is the memory calc from the Wiki: For a rough rule of thumb, Cassandra's internal datastructures will require about memtable_throughput_in_mb * 3 * number of hot CFs + 1G +

Re: Slow network writes

Is it possible that the key 1212 maps to the first node? I am assuming RF=1. You could try random keys to test this theory... Oleg

Re: py_stress error in Cassandra 0.7

Have you generated Cassandra Thrift interface? You will need to install Thrift first: http://wiki.apache.org/cassandra/InstallThrift Then, in the interface directory under Cassandra's home you can run thrift --gen py cassandra.thrift If the above does not install generated cassandra thrift

Re: Slow network writes

ruslan usifov ruslan.usifov at gmail.com writes: 2011/2/3 Oleg Proudnikov olegp at cloudorange.com Is it possible that the key 1212 maps to the first node? I am assuming RF=1. You could try random keys to test this theory... Yes you right 1212 goes to first node. I distribute tokens

Re: How to monitor Cassandra's throughput?

I have posted on Hector ML: http://thread.gmane.org/gmane.comp.db.hector.user/1690 Oleg

How to monitor Cassandra's throughput?

Hi All, Is there a way to tell how many mutations/s my cluster is processing across all column families? Per node value would be OK as well. I see WriteCount per CF per node as well as TotalWriteLatencyMicros. Are they the right metrics to aggregate for this purpose? Thank you very much, Oleg

Re: How to monitor Cassandra's throughput?

Thanks, Aaron! Is StorageProxy only exposed on the seed node? I consistently see it only on a single node that happens to be seed. Oleg

count in 0.7.0

Hi All, Does Cassandra 0.7.0 need to deserialize the complete row in order to count all columns? I know from this ML that Cassandra 0.6 did that. Thank you very much, Oleg

Re: Stress test inconsistencies

Hi All, I was able to run contrib/stress at a very impressive throughput. Single threaded client was able to pump 2,000 inserts per second with 0.4 ms latency. Multithreaded client was able to pump 7,000 inserts per second with 7ms latency. Thank you very much for your help! Oleg

Re: Stress test inconsistencies

I returned to periodic commit log fsync. Jonathan Shook jshook at gmail.com writes: Would you share with us the changes you made, or problems you found?

Re: Stress test inconsistencies

Tyler Hobbs tyler at riptano.com writes: Try using something higher than -t 1, like -t 100.- Tyler Thank you, Tyler! When I run contrib/stress with a higher thread count, the server does scale to 200 inserts a second with latency of 200ms. At the same time Windows desktop scales to 900

Re: Stress test inconsistencies

Brandon Williams driftx at gmail.com writes: On Tue, Jan 25, 2011 at 1:23 PM, Oleg Proudnikov olegp at cloudorange.com wrote: When I run contrib/stress with a higher thread count, the server does scale to 200 inserts a second with latency of 200ms. At the same time Windows desktop scales

Lost MUTATIONS on several Cassandra nodes - no impact on the client

Hi All, Could you please help me understand the impact of this behaviour? I am running a 6 node 0.7-rc4 Cassandra cluster with RF=2 6 Hector clients (one per node) are performing single-threaded batch load running on the same servers. CL=ONE. Client performs one simple small query and an

UnserializableColumnFamilyException: Couldn't find cfId

Hi All, Could you please help me understand the impact on my data? I am running a 6 node 0.7-rc4 Cassandra cluster with RF=2. Schema was defined when the cluster was created and did not change. I am doing batch load with CL=ONE. The cluster is under some stress in memory and I/O. Each node has