Re: Using Cassandra as cache

2014-06-23 Thread Pavel Kogan
Thank you all, The issue was resolved (or more exactly bypassed) by adding small python script running hourly in cron on 1-2 nodes, which pre-provision next hour keyspace. One hour is definitely enough time for scheme propagation. Regards, Pavel On Sun, Jun 22, 2014 at 9:35 AM, Robert Stupp

Re: Using Cassandra as cache

2014-06-22 Thread Robert Stupp
Am 21.06.2014 um 00:37 schrieb Pavel Kogan : > Thanks, > > Is there any code way to know when the scheme finished to settle down? Yep - take a look at com.datastax.driver.core.ControlConnection#waitForSchemaAgreement in the Java Driver source. It basically compares the 'schema_version' column

Re: Using Cassandra as cache

2014-06-20 Thread Robert Coli
On Fri, Jun 20, 2014 at 3:09 PM, DuyHai Doan wrote: > @Robert: do we still need to cleanup manually snapshot when truncating ? I remembered that on the 1.2 branch, even though the auto_snapshot param was set to false, truncating leads to snapshot creation that forced us to manually remove the snap

Re: Using Cassandra as cache

2014-06-20 Thread Pavel Kogan
Thanks, Is there any code way to know when the scheme finished to settle down? Can working RF=2 and CL=ANY result in any problem with consistency? I am not sure I can have problems with consistency if I don't do updates, only writes and reads. Can I? By the way I am using Cassandra 2.0.8. Pavel

Re: Using Cassandra as cache

2014-06-20 Thread Pavel Kogan
Thanks Robert, Can you please explain what problems DROP/CREATE keyspace may cause? Seems like truncate working per column family and I have up to 10. What I should I delete from disk in that case? I can't delete whole folder right? I need to delete all content under each cf folder, but not folder

Re: Using Cassandra as cache

2014-06-20 Thread DuyHai Doan
Schema propagation takes times: https://issues.apache.org/jira/browse/CASSANDRA-5725 @Robert: do we still need to cleanup manually snapshot when truncating ? I remembered that on the 1.2 branch, even though the auto_snapshot param was set to false, truncating leads to snapshot creation that forced

Re: Using Cassandra as cache

2014-06-20 Thread Robert Coli
On Fri, Jun 20, 2014 at 2:48 PM, Pavel Kogan wrote: > So what we did is creating every hour new keyspace named _MM_dd_HH and > when disk becomes full, script running in crontrab on each node drops > keyspace with "IF EXISTS" flag, and deletes whole keyspace folder. That way > whole process is

Re: Using Cassandra as cache

2014-06-20 Thread Robert Stupp
Am 20.06.2014 um 23:48 schrieb Pavel Kogan : > 1) When new keyspace with its columnfamilies is being just created (every > round hour), sometimes other modules failed to read/write data, and we lose > request. Can it be that creation of keyspace and columnfamilies is async > operation or there