Sync mongodb to remote, problem with mongooplog

[rr Feng]

My environment:

- local repl cluster with node A B C, A is the primary.

- local replset name: RSL

- remote: a mechine M, not running mongod

- remote: a config file has been prepared.

My step:

- stop local node C

- rsync data dir to M

- start mongod withou --replSet

- save last oplog entry to local.temp( with time T)

- update the local.system.replset as new cluster

- drop local.oplog.rs

- insert the last oplog entry from local.temp

- restart mongod with --replSet

now the new mongod is running ok

- start local node C

- calc the oplog timestamp shift  (NOW - T)

- run mongooplog --from C --to M -s $((NOW - T + 10))

Please tell me, is this steps OK?

and a problem: 

mongooplog start to fetch oplog and applyOps to M, but it runs slow, the oplog lag is growthing....

how could I fix this? 

[rr Feng]

One more problem:

mongooplog say "2016-10-14T14:55:35.805+0800 done applying oplog entries" and stopped.

but at that time, there  were millions of oplog to fetch and apply, why?

[Kevin Adistambha]

Hi,

My environment:

• local repl cluster with node A B C, A is the primary.

• local replset name: RSL

• remote: a mechine M, not running mongod

• remote: a config file has been prepared.

My step:

• stop local node C

• rsync data dir to M

• start mongod withou —replSet

• save last oplog entry to local.temp( with time T)

• update the local.system.replset as new cluster

• drop local.oplog.rs

• insert the last oplog entry from local.temp

• restart mongod with —replSet

• 
  now the new mongod is running ok

• start local node C

• calc the oplog timestamp shift (NOW - T)

• run mongooplog —from C —to M -s $((NOW - T + 10))

Please tell me, is this steps OK?

and a problem:
mongooplog start to fetch oplog and applyOps to M, but it runs slow, the oplog lag is growthing….

how could I fix this?

Could you elaborate on what you are trying to achieve? Are you trying to make a backup of one replica set and restore it on a new replica set, or are you trying to attach a new remote node to an existing replica set?

If you are trying to restore an existing replica set data on a new replica set, you should follow the steps outlined in the Restore a Replica Set from MongoDB Backups page instead of manually modifying the contents of the local database, especially the oplog collection.

If you are trying to add a new remote node to an existing replica set, you could follow the procedure outlined in the Add Members to a Replica Set page

Best regards,
Kevin

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