http://www.datastax.com/support-forums/topic/commit-log-is-not-syncng-periodically-and-still-holding-the-yesterdays-data Software, Support, and Training for Apache Cassandra en-US Wed, 22 May 2013 06:39:12 +0000 http://bbpress.org/?v=1.0.3 q http://www.datastax.com/support-forums/search.php http://www.datastax.com/support-forums/topic/commit-log-is-not-syncng-periodically-and-still-holding-the-yesterdays-data#post-7167 Mon, 29 Oct 2012 16:31:32 +0000 Sven 7167@http://www.datastax.com/support-forums/ <p>commitlog_segment_size_in_mb controls the size of the individual commitlog files. So I wouldn't expect that to affect what data is visible when. </p> <p>When you say updates are not reflect immediately in the frontend, what exactly are you talking about? Do you have a more concrete example of what you are doing/observing? </p> http://www.datastax.com/support-forums/topic/commit-log-is-not-syncng-periodically-and-still-holding-the-yesterdays-data#post-7139 Sat, 27 Oct 2012 10:25:00 +0000 gopia 7139@http://www.datastax.com/support-forums/ <p>Thanks for the reply.. I am bit confused between commitlog_segment_size_in_mb and commitlog_total_space_in_mb. I changed the commitlog_total_space_in_mb value to a less value to make the updates reflect immediately on the front-end. </p> http://www.datastax.com/support-forums/topic/commit-log-is-not-syncng-periodically-and-still-holding-the-yesterdays-data#post-7134 Sat, 27 Oct 2012 04:23:55 +0000 Sven 7134@http://www.datastax.com/support-forums/ <p>You may be misinterpreting what commitlog_sync_period_in_ms means (please see <a href="http://wiki.apache.org/cassandra/Durability" rel="nofollow">http://wiki.apache.org/cassandra/Durability</a> for a more detailed explanation). It only refers to the interval between fsyncs, which ensures that the data written to the commitlog is committed to disk.</p> <p>A common concern is to keep the size of the commit log small, in which case you may want to consider changing the parameter commitlog_total_space_in_mb. Not sure whether that is you issue though.</p> <p>Are you observing a particular issue that triggers your concern, or in other words, what problem are you trying to solve? </p> http://www.datastax.com/support-forums/topic/commit-log-is-not-syncng-periodically-and-still-holding-the-yesterdays-data#post-7120 Fri, 26 Oct 2012 06:02:01 +0000 gopia 7120@http://www.datastax.com/support-forums/ <p>I am using the 1.1 datastax linux (centos) installer for the cassandra service.</p> <p>The cassandra service is holding the past data and not flushing periodically even thought the commit log sync period is timed out. Please let me know any other setting are required to check.</p> <p>Below are the setting i use in cassandra.yaml</p> <p>commitlog_sync: periodic<br /> commitlog_sync_period_in_ms: 10000</p> <p>commitlog_segment_size_in_mb: 32</p> <p>If i change the commitlog segment size to a lower value than the commit log folder size, then only the cassandra is clearing the commitlogs.</p> <p>Please help me, i am not sure whether the commitlog segment size requires changes to the value. </p>