Public bug reported: [Impact]
When an operator of Juju attempts to restore a backup, it fails with a mongorestore related error[0]. Under the hood, Juju uses the supplied mongo related command line interfaces (mongodump, mongorestore etc), using these in conjunction with the oplog related flags for the former CLIs, the mongorestore fails with the following error: > Failed: restore error: error applying oplog: applyOps: applyOps had one or more errors applying ops The only work around for Juju at the moment is to update mongod, so that it carries the following commit[1]. MongoDB have an identical issue, under a different name, which fixes this[2], but there is unfortunately no work around without upgrading mongod so it caries the former commit. The original investigation around Juju failing to restore a previous dump can be seen here[3] I've verified with the 3.6.11 and the same restore, worked fine. [Test Case] The following test case doesn't require Juju, and can be replicated quite easily inside a lxc container. It may require 2 or 3 goes, depending on timings of the creation of the index and the mongodump, but I've been getting this consistently. You can also find instructions in one pastebin[4] // Launch a container lxc launch ubuntu:18.04 mongo lxc exec mongo bash // Install a version of mongo that Juju is using. sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 58712A2291FA4AD5 sudo bash -c 'echo "deb http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.6 multiverse" > /etc/apt/sources.list.d/mongodb-org-3.6.list' sudo apt update sudo apt-get install -y mongodb-org=3.6.3 mongodb-org-server=3.6.3 mongodb-org-shell=3.6.3 mongodb-org-mongos=3.6.3 mongodb-org-tools=3.6.3 // Apply the patch to /etc/mongod.conf to enable the replication - this is required. --- /etc/mongod.conf 2019-03-22 17:17:10.530432761 +0000 +++ /etc/mongod.conf 2019-03-22 17:16:51.602528908 +0000 @@ -32,8 +32,7 @@ #operationProfiling: -replication: - replSetName: "rs0" +#replication: #sharding: // Start the mongod service systemctl enable mongod.service systemctl start mongod.service // not required, but helps diagnose bsondump snap install jq // launch the mongo CLI, running each command mongo --eval "rs.initiate()" mongo --eval "rs.status()" mongo --eval "db.foo.insert({'foo':'bar'})" mongo --eval "db.foo.createIndex({'bar':1})" // Get the dump mongodump --oplog // check if it's going to fail // if the output contains a createIndex, but doesn't contain an oid then it'll fail. bsondump dump/oplog.bson | jq // Drop the foo collection, so we don't get any duplication errors mongo --eval "db.foo.drop()" // Now restore the dump mongorestore --oplogReplay dump/ // It should fail with 2019-03-22T17:26:28.034+0000 preparing collections to restore from 2019-03-22T17:26:28.035+0000 reading metadata for test.foo from dump/test/foo.metadata.json 2019-03-22T17:26:28.053+0000 restoring test.foo from dump/test/foo.bson 2019-03-22T17:26:28.056+0000 restoring indexes for collection test.foo from metadata 2019-03-22T17:26:28.062+0000 finished restoring test.foo (1 document) 2019-03-22T17:26:28.062+0000 replaying oplog 2019-03-22T17:26:28.064+0000 Failed: restore error: error applying oplog: applyOps: applyOps had one or more errors applying ops [Other Info] 0. https://paste.ubuntu.com/p/9r9pYc9g9D/ 1. https://github.com/mongodb/mongo/commit/0d0ba866052fd2b9ceaaa66c2b725a02822b102d 2. https://jira.mongodb.org/browse/SERVER-36951 3. https://bugs.launchpad.net/juju/+bug/1818831 4. https://paste.ubuntu.com/p/HJsDf5yNkS/ ** Affects: mongodb (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1821391 Title: mongorestore fails with createIndexes command in oplog To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mongodb/+bug/1821391/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
