Hello, when I set 'commitlog_sync: batch' on all the nodes, it turns out to be very poor performance for the write operation. Is anyone of had ever do some testing under the batch mode.
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Commitlog sync mode(5 posts) (2 voices)
No wonder why you experience poor write performance take a look at the comment in conf/cassandra.yaml
When in batch mode, Cassandra won't ack writes until the commit log
has been fsynced to disk. It will wait up to
commitlog_sync_batch_window_in_ms milliseconds for other writes, before
performing the sync.
Thanks for your reply. Do you mean that the batch mode can achieve performance close to periodic mode.
As it won't be returning write responses until batch window is closed that means that batch mode is more suitable for not intensive write loads and won't be able to archive the same performance as periodic on write intensive work loads.
OK,I get it. Thank you!!