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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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Affects Version/s: 3.0.4
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Component/s: Admin
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ALL
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3
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Hello,
I have a replica set MongoDB 3.0.4 with stable load (60-100 inserts, 20-30 updates, 10 queries). Sometimes I do bulk inserts like 20K 30K and after this the CPU goes high even though I am done with the operation and there is nothing else.
In MMS when I look at the CPU of a fresh MongoDB (just started) everything is normal. But when I use bulk write to insert 20k or 40k or any job that uses cache the CPU usage (specially user usage) goes over 100%. The servers are isolated from any other applications and they only use MongoDB and I check with other monitoring tools it's all MongoDB. When I restart the MongoDB it all goes away.
How I start my replica:
mongod --storageEngine wiredTiger --wiredTigerCacheSizeGB=2 --dbpath /data/ --replSet rs0 --fork --logpath /data/fork.log
I also tried different cache size like 5 or 10 and it was the same. The only thing that looks different before bulk inserts and after bulk inserts is the cache usage in MMS.
Stats:
rs0:PRIMARY> db.stats()
{
"db" : "test",
"collections" : 66,
"objects" : 1943772773,
"avgObjSize" : 741.1523292167237,
"dataSize" : 1440631718177,
"storageSize" : 736019369984,
"numExtents" : 0,
"indexes" : 193,
"indexSize" : 27145035776,
"ok" : 1
}
insert query update delete getmore command % dirty % used flushes vsize res qr|qw ar|aw netIn netOut conn set repl time
localhost:27017 *33 3 *10 *0 0 9|0 6.1 33.8 0 5.8G 5.2G 0|3 1|0 1k 407k 112 rs0 SEC 10:38:14
mongodb-replica1:27017 31 *0 18 *0 34 8|0 22.0 50.5 0 2.2G 1.5G 0|1 1|0 50k 62k 107 rs0 PRI 10:38:14
mongodb-replica2:27017 *33 3 *10 *0 0 10|0 6.1 33.8 0 5.8G 5.2G 0|3 1|0 1k 407k 112 rs0 SEC 10:38:14
localhost:27017 *41 10 *14 *0 0 10|0 6.1 33.8 0 5.8G 5.2G 0|3 1|0 3k 386k 112 rs0 SEC 10:38:15
mongodb-replica1:27017 39 *0 14 *0 42 11|0 22.0 50.5 0 2.2G 1.5G 0|1 1|0 54k 68k 107 rs0 PRI 10:38:15
mongodb-replica2:27017 *41 10 *14 *0 0 9|0 6.1 33.8 0 5.8G 5.2G 0|3 2|0 3k 386k 112 rs0 SEC 10:38:15
localhost:27017 *45 6 *19 *0 0 14|0 6.1 33.8 0 5.8G 5.2G 0|3 2|0 2k 223k 112 rs0 SEC 10:38:16
mongodb-replica1:27017 34 *0 19 *0 36 18|0 22.0 50.5 0 2.2G 1.5G 0|0 1|1 50k 64k 107 rs0 PRI 10:38:16
mongodb-replica2:27017 *45 6 *19 *0 0 14|0 6.1 33.8 0 5.8G 5.2G 0|3 2|0 2k 223k 112 rs0 SEC 10:38:16
Please let me know if you need more information.
Thanks
