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https://issues.apache.org/jira/browse/CASSANDRA-12173?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16092623#comment-16092623
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Jeff Jirsa commented on CASSANDRA-12173:
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The sstables are ordered by decorated key, which is going to be basically
random. The fact that a materialized view statement happens to be first is
probably just chance. I haven't read any of the MV code, but it seems very
unlikely that it turns on tracing (but I suppose nothing is impossible).
> Materialized View may turn on TRACING
> -------------------------------------
>
> Key: CASSANDRA-12173
> URL: https://issues.apache.org/jira/browse/CASSANDRA-12173
> Project: Cassandra
> Issue Type: Bug
> Components: Materialized Views
> Reporter: Hiroshi Usami
>
> We observed this in our test cluster(C*3.0.6), but TRAING was OFF apparently.
> After creating Materialized View, the Write count jumped up to 20K from 5K,
> and the ViewWrite rose up to 10K.
> This is supposed to be done by MV, but some nodes which had 14,000+ SSTables
> in the system_traces directory went down in a half day, because of running
> out of file descriptors.
> {code}
> Counting by: find /var/lib/cassandra/data/system_traces/ -name "*-Data.db"|wc
> -l
> node01: 0
> node02: 3
> node03: 1
> node04: 0
> node05: 0
> node06: 0
> node07: 2
> node08: 0
> node09: 0
> node10: 0
> node11: 2
> node12: 2
> node13: 1
> node14: 7
> node15: 1
> node16: 5
> node17: 0
> node18: 0
> node19: 0
> node20: 0
> node21: 1
> node22: 0
> node23: 2
> node24: 14420
> node25: 0
> node26: 2
> node27: 0
> node28: 1
> node29: 1
> node30: 2
> node31: 1
> node32: 0
> node33: 0
> node34: 0
> node35: 14371
> node36: 0
> node37: 1
> node38: 0
> node39: 0
> node40: 1
> {code}
> In node24, the sstabledump of the oldest SSTable in system_traces/events
> directory starts with:
> {code}
> [
> {
> "partition" : {
> "key" : [ "e07851d0-4421-11e6-abd7-59d7f275ba79" ],
> "position" : 0
> },
> "rows" : [
> {
> "type" : "row",
> "position" : 30,
> "clustering" : [ "e07878e0-4421-11e6-abd7-59d7f275ba79" ],
> "liveness_info" : { "tstamp" : "2016-07-07T09:04:57.197Z", "ttl" :
> 86400, "expires_at" : "2016-07-08T09:04:57Z", "expired" : true },
> "cells" : [
> { "name" : "activity", "value" : "Parsing CREATE MATERIALIZED VIEW
> ...
> {code}
> So this could be the begining of TRACING ON implicitly. In node35, the oldest
> one also starts with the "Parsing CREATE MATERIALIZED VIEW".
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