On 05/04/2011 09:56 AM, Florin Andrei wrote: > On 05/04/2011 09:44 AM, Srinivas Eeda wrote: >> Yes, there is locking involved. Extending a file needs an exclusive >> lock. Grepping a file needs read lock. If the same node(lets call it >> writer node) does extending and grepping, then grep already has a >> compatible lock and the data is also cached on this node. When another >> node does the grep(lets call it reader node), then it needs to acquire >> read lock. This requires the writer node to down grade the lock which >> requires the node to flush data to the disk. Then the reader node has to >> read the data to the cache. So when grep is done on the reader node, >> there are additional messages and additional I/O's to the disk are done. > Any workarounds? > > Obviously doing read and append on the same node is one way. > > Could the logger extend the file in a different way? The software is > homegrown, we could modify it to make it more OCFS2-friendly, if that's > possible.
Don't append as often. IOW, make large appends and not few bytes at a time like all loggers. > OCFS2 settings to tinker with? Cache coherency is not a configurable option. _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users
