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Type:
Bug
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Resolution: Duplicate
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Priority:
Major - P3
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None
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Affects Version/s: 3.0.3
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Component/s: mongodump
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None
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Kernel Tools Iteration 4, Kernel Tools Iteration 5
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v3.0
Intro
I have a job exporting a set of documents from collections on a sharded cluster using mongodump to BSON files which are later imported on other type of DBs.
Since maintaining a strong consistency from our mongodb cluster and the other DBs is important to us, we implemented a three way check on the number of exported documents :
- count the targeted documents using a normal query
- parse and count the mongodump exported documents count
- count the number of imported documents from the BSON files into the other DBs
- everything is okay when all counts match obviously !
We are migrating this cluster to 3.0.3. It was doing okay while the primaries and secondaries were still running under MMAPv1 : the number of documents extracted by mongodump was the same as the number found in the bson.
But since the migration to mongodb 3.0.3 wiredTiger on the SECONDARIES (primaries still run MMAPv1), a difference is visible between the total number of documents than mongodump said to have extracted, and the actual number of records found in the bson!
Mongodump
mongodump
# mongodump --host 'modb-1:27017' --db 'LA_VERITAY' --verbose --collection 'LA_VERITAY' --query '{"seen": {"$gte": {"$date": 1432058400000}, "$lt": {"$date": 1432135349000}}}' --out '/tmp/exports/20150519/LA_VERITAY/LA_VERITAY' 2015-05-20T17:27:54.035+0200 dumping with 32 job threads 2015-05-20T17:27:54.035+0200 writing LA_VERITAY.LA_VERITAY to /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson 2015-05-20T17:27:54.798+0200 4314985 documents 2015-05-20T17:27:57.035+0200 [........................] LA_VERITAY.LA_VERITAY 0/4314985 (0.0%) 2015-05-20T17:28:00.035+0200 [........................] LA_VERITAY.LA_VERITAY 100/4314985 (0.0%) 2015-05-20T17:28:06.035+0200 [........................] LA_VERITAY.LA_VERITAY 161436/4314985 (3.7%) [...] 2015-05-20T17:35:00.035+0200 [#######################.] LA_VERITAY.LA_VERITAY 4210397/4314985 (97.6%) 2015-05-20T17:35:01.411+0200 writing LA_VERITAY.LA_VERITAY metadata to /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.metadata.json 2015-05-20T17:35:01.444+0200 done dumping LA_VERITAY.LA_VERITAY 2015-05-20T17:35:01.444+0200 done
- mongodump reports exporting 4314985 documents.
bsondump
bsondump --objcheck /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson 1> /dev/null
2015-05-20T19:49:42.547+0200 4314084 objects found
- bsondump reports exporting 4314084 documents.
Restore (with --objcheck and --drop)
mongorestore -v --drop --objcheck --host=localhost --port=27017 --db=LA_VERITAY --collection=LA_VERITAY /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson
2015-05-20T18:34:04.552+0200 using write concern: w='1', j=false, fsync=false, wtimeout=0 2015-05-20T18:34:04.553+0200 checking for collection data in /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson 2015-05-20T18:34:04.553+0200 found metadata for collection at /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.metadata.json 2015-05-20T18:34:04.554+0200 reading metadata file from /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.metadata.json 2015-05-20T18:34:04.554+0200 no collection options to restore 2015-05-20T18:34:04.554+0200 restoring LA_VERITAY.LA_VERITAY from file /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson 2015-05-20T18:34:04.554+0200 file /tmp/exports/20150519/LA_VERITAY/LA_VERITAY/LA_VERITAY/LA_VERITAY.bson is 506070804 bytes 2015-05-20T18:34:07.553+0200 [##......................] LA_VERITAY.LA_VERITAY 52.5 MB/482.6 MB (10.9%) 2015-05-20T18:34:10.553+0200 [####....................] LA_VERITAY.LA_VERITAY 96.1 MB/482.6 MB (19.9%) 2015-05-20T18:34:13.553+0200 [######..................] LA_VERITAY.LA_VERITAY 137.0 MB/482.6 MB (28.4%) 2015-05-20T18:34:16.553+0200 [########................] LA_VERITAY.LA_VERITAY 177.6 MB/482.6 MB (36.8%) 2015-05-20T18:34:19.553+0200 [##########..............] LA_VERITAY.LA_VERITAY 216.5 MB/482.6 MB (44.9%) 2015-05-20T18:34:22.553+0200 [############............] LA_VERITAY.LA_VERITAY 254.3 MB/482.6 MB (52.7%) 2015-05-20T18:34:25.553+0200 [##############..........] LA_VERITAY.LA_VERITAY 292.6 MB/482.6 MB (60.6%) 2015-05-20T18:34:28.553+0200 [###############.........] LA_VERITAY.LA_VERITAY 313.9 MB/482.6 MB (65.0%) 2015-05-20T18:34:31.553+0200 [################........] LA_VERITAY.LA_VERITAY 339.9 MB/482.6 MB (70.4%) 2015-05-20T18:34:34.553+0200 [##################......] LA_VERITAY.LA_VERITAY 380.5 MB/482.6 MB (78.8%) 2015-05-20T18:34:37.553+0200 [####################....] LA_VERITAY.LA_VERITAY 409.1 MB/482.6 MB (84.8%) 2015-05-20T18:34:40.553+0200 [######################..] LA_VERITAY.LA_VERITAY 446.3 MB/482.6 MB (92.5%) 2015-05-20T18:34:43.553+0200 [#######################.] LA_VERITAY.LA_VERITAY 468.9 MB/482.6 MB (97.2%) 2015-05-20T18:34:44.930+0200 restoring indexes for collection LA_VERITAY.LA_VERITAY from metadata 2015-05-20T18:45:08.891+0200 finished restoring LA_VERITAY.LA_VERITAY 2015-05-20T18:45:08.891+0200 done
DB Stats
db.stats()
{
"ns" : "LA_VERITAY.LA_VERITAY",
"count" : 4314084,
"size" : 965267776,
"avgObjSize" : 223,
"storageSize" : 1164976128,
"numExtents" : 18,
"nindexes" : 5,
"lastExtentSize" : 307535872,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 1,
"totalIndexSize" : 1352318576,
"indexSizes" : {
"_id_" : 185914064,
"xxx_1_yyy_1" : 429640624,
"yyy_1_xxx_1" : 431284000,
"hhh_1" : 146121472,
"jjj_-1" : 159358416
},
"ok" : 1
}
- restored documents count is 4314084 !
- duplicates
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TOOLS-779 Log final number of documents dumped/restored in a collection
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- Closed
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