MongoDB初始同步重复失败（Azure VM上的Ubuntu 16.04上的Mongodb 3.2）

Question

• I have a one member mongod instance (Server1) with a very large DB with 2.5 million documents (Each document is very big) and 4 indices.
• Then I added another machine (Server2)to this replica set. Mongod on Server2 takes about 5 hours to fetch all the documents in this big database.

• After all the documents are fetched by Server2, It starts making secondary indices. It takes around 3 hours for indices to get finished.

  • Immediately after completing building the secondary indices, It tries to connect to primary and finds that socket is expired and timed out.

  • At having received a timeout error it (Server2) simply drops all databases and starts the initial sync again.

  • The snippet from logs is below:

 2016-05-25T11:50:36.053+0000 I - [rsSync] Index Build: 2211700/2215091 99% 2016-05-25T11:50:39.221+0000 I - [rsSync] Index Build: 2212000/2215091 99% 2016-05-25T11:50:43.300+0000 I - [rsSync] Index Build: 2212300/2215091 99% 2016-05-25T11:50:46.103+0000 I - [rsSync] Index Build: 2212500/2215091 99% 2016-05-25T11:50:49.068+0000 I - [rsSync] Index Build: 2212800/2215091 99% 2016-05-25T11:50:52.218+0000 I - [rsSync] Index Build: 2213600/2215091 99% 2016-05-25T11:50:55.439+0000 I - [rsSync] Index Build: 2214500/2215091 99% 2016-05-25T11:50:58.738+0000 I - [rsSync] Index Build: 2214700/2215091 99% 2016-05-25T11:51:13.223+0000 I - [rsSync] Index: (2/3) BTree Bottom Up Progress: 536600/2215091 24% 2016-05-25T11:51:23.285+0000 I - [rsSync] Index: (2/3) BTree Bottom Up Progress: 1984500/2215091 89% 2016-05-25T11:51:24.317+0000 I INDEX [rsSync] done building bottom layer, going to commit 2016-05-25T11:51:24.508+0000 I INDEX [rsSync] build index done. scanned 2215091 total records. 10491 secs 2016-05-25T11:51:25.082+0000 I NETWORK [rsSync] Socket say send() errno:110 Connection timed out xx.xx.xx.xx:27017 2016-05-25T11:51:25.106+0000 E REPL [rsSync] 9001 socket exception [SEND_ERROR] server [xx.xx.xx.xx:27017] 2016-05-25T11:51:25.106+0000 E REPL [rsSync] initial sync attempt failed, 9 attempts remaining 2016-05-25T11:51:30.106+0000 I REPL [rsSync] initial sync pending 2016-05-25T11:51:30.433+0000 I REPL [ReplicationExecutor] syncing from: xx.xx.xx.xx:27017 2016-05-25T11:51:30.563+0000 I REPL [rsSync] initial sync drop all databases 2016-05-25T11:51:30.564+0000 I STORAGE [rsSync] dropAllDatabasesExceptLocal 42 2016-05-25T11:51:31.925+0000 I JOURNAL [rsSync] journalCleanup... 2016-05-25T11:51:31.925+0000 I JOURNAL [rsSync] removeJournalFiles 2016-05-25T11:51:32.331+0000 I JOURNAL [rsSync] journalCleanup... 2016-05-25T11:51:32.332+0000 I JOURNAL [rsSync] removeJournalFiles 2016-05-25T11:51:32.489+0000 I JOURNAL [rsSync] journalCleanup... 2016-05-25T11:51:32.489+0000 I JOURNAL [rsSync] removeJournalFiles 

• It has been very very frustrating trying to sync this replica set. It keeps doing initial sync over and over again. Any help is highly appreciated.

Answer 1

Perhaps you can use this as a workaround until the problem is diagnosed:

https://docs.mongodb.com/manual/tutorial/resync-replica-set-member/#replica-set-resync-by-copying