Pbm resore DB without indexes

MongoDB Percona Backup for MongoDB
1

I have a Percona replica set and PBM installed. Backup files were copied to separate folder in installed on another test replica. Restored replica differs from original back up, no indexes. Is this expected? Is it possible to backup Percona Mongo with PBM including indexes? Mongodump-mogorestore restore the whole DB, with indexes, why PBM is missing it?

2

Hi, it is not expected your restored data is missing indexes. Did you manually restore? please provide more details. For reference, you are supposed to follow the procedure here Restore a backup - Percona Backup for MongoDB to restore to a different environment.

3

hi Ivan.

What do you mean-manually? I resored data using “pbm restore $timestamp”, $timestamp I take from “pbm list” command. Where pbm store collection metadata? I see only files like mydb.customers.s2. I suspect this might happen because of non-default index compression applied, will investigate it.

P.S. I see index metadata in the file metadata.json in each “$timestamp/mydb” folder, so it does exists. Why pbm failed to restore indexes? Also I found that the local DB is very big after backup restore.

4

what I meant before is to ask if you manually restored using mongorestore instead of pbm commands, which is not supported. I see from your reply that you did not do that, so we are good. What do you mean by non-default index compression? please provide more details about your environment as there might be some edge case.

5

I have restored the DB with “pbm restore”, see no indexes, then using native Mongo tools: mongodump-mongorestore, see indexes do exist.
Non-default index compression I mean this (part of /etc/mongod.conf):

storage:
  dbPath: /data
  engine: wiredTiger
  oplogMinRetentionHours: 8
  wiredTiger:
    collectionConfig:
      blockCompressor: zstd
    engineConfig:
      journalCompressor: zstd
    indexConfig:
      prefixCompression: true

I suspect it started after the compression was added (block, journal, prefix), but not sure need to check it.

6

Index prefix compression is turned on by default. I see you changed the compressor to zstd also. Can you send us some logs from the agent? might be better to open a ticket Jira - Percona JIRA with all the info so engineering can take a look