add warning to multithreaded_compaction
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/ca02176f Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/ca02176f Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/ca02176f Branch: refs/heads/cassandra-1.2 Commit: ca02176fc0cde6eee6b0f278ece58ce8ce202d18 Parents: 36b183f Author: Jonathan Ellis <jbel...@apache.org> Authored: Tue Dec 11 12:37:47 2012 -0600 Committer: Jonathan Ellis <jbel...@apache.org> Committed: Tue Dec 11 12:37:47 2012 -0600 ---------------------------------------------------------------------- conf/cassandra.yaml | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/ca02176f/conf/cassandra.yaml ---------------------------------------------------------------------- diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml index c4732db..543ad65 100644 --- a/conf/cassandra.yaml +++ b/conf/cassandra.yaml @@ -381,12 +381,15 @@ in_memory_compaction_limit_in_mb: 64 # Uncomment to make compaction mono-threaded, the pre-0.8 default. #concurrent_compactors: 1 -# Multi-threaded compaction. When enabled, each compaction will use -# up to one thread per core, plus one thread per sstable being merged. -# This is usually only useful for SSD-based hardware: otherwise, -# your concern is usually to get compaction to do LESS i/o (see: -# compaction_throughput_mb_per_sec), not more. -multithreaded_compaction: false +# multithreaded_compaction: false. When enabled, each compaction will +# use up to one thread per core, plus one thread per sstable being +# merged. This is usually only useful for SSD-based hardware: +# otherwise, your concern is usually to get compaction to do LESS i/o +# (see: compaction_throughput_mb_per_sec), not more. +# +# WARNING: this setting has caused compaction deadlocks for multiple +# users (see CASSANDRA-4492). It is recommended to leave this off +# unless you are prepared to help troubleshoot. # Throttles compaction to the given total throughput across the entire # system. The faster you insert data, the faster you need to compact in