On 03/31/2017 06:44 AM, Nikhil Utane wrote: > We are seeing this log in pacemaker.log continuously. > > Mar 31 17:13:01 [6372] 0005B932ED72 cib: info: > crm_compress_string: Compressed 436756 bytes into 14635 (ratio 29:1) in > 284ms > > This looks to be the reason for high CPU. What does this log indicate?
If a cluster message is larger than 128KB, pacemaker will compress it (using BZ2) before transmitting it across the network to the other nodes. This can hit the CPU significantly. Having a large resource definition makes such messages more common. There are many ways to sync a configuration file between nodes. If the configuration rarely changes, a simple rsync cron could do it. Specialized tools like lsyncd are more responsive while still having a minimal footprint. DRBD or shared storage would be more powerful and real-time. If it's a custom app, you could even modify it to use something like etcd or a NoSQL db. > > -Regards > Nikhil > > > On Fri, Mar 31, 2017 at 12:08 PM, Nikhil Utane > <[email protected] <mailto:[email protected]>> wrote: > > Hi, > > In our current design (which we plan to improve upon) we are using > the CIB file to synchronize information across active and standby nodes. > Basically we want the standby node to take the configuration that > was used by the active node so we are adding those as resource > attributes. This ensures that when the standby node takes over, it > can read all the configuration which will be passed to it as > environment variables. > Initially we thought the list of configuration parameters will be > less and we did some prototyping and saw that there wasn't much of > an issue. But now the list has grown it has become close to 300 > attributes. (I know this is like abusing the feature and we are > looking towards doing it the right way). > > So I have two questions: > 1) What is the best way to synchronize such kind of information > across nodes in the cluster? DRBD? Anything else that is simpler? > For e.g. instead of syncing 300 attributes i could just sync up the > path to a file. > > 2) In the current design, is there anything that I can do to reduce > the CPU utilization of cib process? Currently it regularly takes > 30-50% of the CPU. > Any quick fix that I can do which will bring it down? For e.g. > configure how often it synchronizes etc? > > -Thanks > Nikhil _______________________________________________ Users mailing list: [email protected] http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
