Mutation of 17076203 bytes is too large for the maxiumum size of 16777216

Question

I have \"commitlog_segment_size_in_mb: 32\" in the cassandra settings but the error below indicates maximum size is 16777216, which is about 16mb. Am I looking at the correc

Answer 1

You are looking at the correct parameter in your .yaml. The maximum write size C* will allow is half of the commit_log_segment_size_in_mb, default is 32mb so the default max size will be 16mb.

Background

commit_log_segment_size_in_mb represents your block size for commit log archiving or point-in-time backup. These are only active if you have configured archive_command or restore_command in your commitlog_archiving.properties file.

Answer 2

Its the correct setting.. This means Cassandra will discard this write as it exceeds 50% of the configured commit log segment size. So set the parameter commitlog_segment_size_in_mb: 64 in Cassandra.yaml of each node in cluster and restart each node to take effect the changes.

Cause: By design intent the maximum allowed segment size is 50% of the configured commit_log_segment_size_in_mb. This is so Cassandra avoids writing segments with large amounts of empty space.

To elaborate; up to two 32MB segments will fit into 64MB, however 40MB will only fit once leaving a larger amount of unused space.

reference link from datastax:

https://support.datastax.com/hc/en-us/articles/207267063-Mutation-of-x-bytes-is-too-large-for-the-maxiumum-size-of-y-