Hi, thanks for answer.
what I don't understand is:
- why there are attempts of read repair if repair chances are 0.0 ?- what can
be cause for big mutation size?- why hinted handoffs didn't prevent
inconsistency? (because of big mutation size?)
Thanks.
On Tuesday, January 1, 2019 9:41 PM, Jeff Jirsa <jji...@gmail.com> wrote:
Read repair due to digest mismatch and speculative retry can both cause some
behaviors that are hard to reason about (usually seen if a host stops accepting
writes due to bad disk, which you havent described, but generally speaking,
there are times when reads will block on writing to extra replicas).
The patch from https://issues.apache.org/jira/browse/CASSANDRA-10726 changes
this behavior significantly.
The last message in this thread (about huge read repair mutations) suggests
that your writes during the bounce got some partitions quite out of sync, and
hints aren't replaying fast enough to fill in the gaps before you read, and the
read repair is timing out. The read repair timing out wouldn't block the read
after 10726, so if you're seeing read timeouts right now, what you probably
want to do is run repair or read much smaller pages so that read repair
succeeds, or increase your commitlog segment size from 32M to 128M or so until
the read repair actually succeeds.
On Tue, Jan 1, 2019 at 12:18 AM Vlad <qa23d-...@yahoo.com.invalid> wrote:
Hi All and Happy New Year!!!
This year started with Cassandra 3.11.3 sometimes forces level ALL despite
query level LOCAL_QUORUM (actually there is only one DC) and it fails with
timeout.
As far as I understand, it can be caused by read repair attempts (we see
"DigestMismatch" errors in Cassandra log), but table has no read repair
configured:
AND bloom_filter_fp_chance = 0.01
AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
AND comment = ''
AND compaction = {'class':
'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy',
'max_threshold': '32', 'min_threshold': '4'}
AND compression = {'chunk_length_in_kb': '64', 'class':
'org.apache.cassandra.io.compress.LZ4Compressor'}
AND crc_check_chance = 1.0
AND dclocal_read_repair_chance = 0.0
AND default_time_to_live = 0
AND gc_grace_seconds = 864000
AND max_index_interval = 2048
AND memtable_flush_period_in_ms = 0
AND min_index_interval = 128
AND read_repair_chance = 0.0
AND speculative_retry = '99PERCENTILE';
Any suggestions?
Thanks.
