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Percona Backup for MongoDB diagnostics tools

Percona Backup for MongoDB provides diagnostics tools to operate data backups.

pbm-speed-test

pbm-speed-test allows field-testing compression and backup upload speed of logical backups. You can use it:

  • To check performance before starting a backup

  • To find out what slows down the running backup

By default, pbm-speed-test operates with fake semi random data documents. To run pbm-speed-test on a real collection, provide a valid MongoDB connection URI string for the --mongodb-uri flag.

Run pbm-speed-test for the full set of available commands.

Compression test

$ pbm-speed-test compression --compression=s2 --size-gb 10

Output:

Test started ....
10.00GB sent in 8s.
Avg upload rate = 1217.13MB/s.

pbm-speed-test compression uses the compression library from the config file and sends a fake semi random data document (1 GB by default) to the black hole storage. (Use the pbm config command to change the compression library).

To test compression on a real collection, pass the --sample-collection flag with the <my_db.my_collection> value.

Run pbm-speed-test compression --help for the full set of supported flags:

$ pbm-speed-test compression --help
usage: pbm-speed-test compression

Run compression test

Flags:
      --help                     Show context-sensitive help (also try
                                 --help-long and --help-man).
      --mongodb-uri=MONGODB-URI  MongoDB connection string
  -c, --sample-collection=SAMPLE-COLLECTION
                                 Set collection as the data source
  -s, --size-gb=SIZE-GB          Set data size in GB. Default 1
      --compression=s2           Compression type
                                 <none>/<gzip>/<snappy>/<lz4>/<s2>/<pgzip>/<zstd>
      --compression-level=COMPRESSION-LEVEL
                                 Compression level (specific to the compression type)
                                 <none>/<gzip>/<snappy>/<lz4>/<s2>/<pgzip>/<zstd>

Upload speed test

$ pbm-speed-test storage --compression=s2

Output

Test started
1.00GB sent in 1s.
Avg upload rate = 1744.43MB/s.

pbm-speed-test storage sends the semi random data (1 GB by default) to the remote storage defined in the config file. Pass the --size-gb flag to change the data size.

To run the test with the real collection’s data instead of the semi random data, pass the --sample-collection flag with the <my_db.my_collection> value.

Run pbm-speed-test storage --help for the full set of available flags:

$ pbm-speed-test storage --help
usage: pbm-speed-test storage

Run storage test

Flags:
      --help                     Show context-sensitive help (also try --help-long and --help-man).
      --mongodb-uri=MONGODB-URI  MongoDB connection string
  -c, --sample-collection=SAMPLE-COLLECTION
                                 Set collection as the data source
  -s, --size-gb=SIZE-GB          Set data size in GB. Default 1
      --compression=s2           Compression type <none>/<gzip>/<snappy>/<lz4>/<s2>/<pgzip>/<zstd>
      --compression-level=COMPRESSION-LEVEL
                                Compression level (specific to the compression type)

Backup progress tracking

If you have a large logical backup, you can track the backup progress in the logs of the pbm-agent that makes it. A line is appended every minute showing bytes copied vs. total size for the current collection.

Start a backup:

$ pbm backup

Check backup progress:

  1. Check what pbm-agent makes the backup:

    pbm logs
    
  2. Connect to the mongod server where the pbm-agent is running and check its logs

    $ journalctl -u pbm-agent.service
    

    Sample output:

    2020/05/06 21:31:12 Backup 2020-05-06T18:31:12Z started on node rs2/localhost:28018
    2020-05-06T21:31:14.797+0300 writing admin.system.users to archive on stdout
    2020-05-06T21:31:14.799+0300 done dumping admin.system.users (2 documents)
    2020-05-06T21:31:14.800+0300 writing admin.system.roles to archive on stdout
    2020-05-06T21:31:14.807+0300 done dumping admin.system.roles (1 document)
    2020-05-06T21:31:14.807+0300 writing admin.system.version to archive on stdout
    2020-05-06T21:31:14.815+0300 done dumping admin.system.version (3 documents)
    2020-05-06T21:31:14.816+0300 writing test.testt to archive on stdout
    2020-05-06T21:31:14.829+0300 writing test.testt2 to archive on stdout
    2020-05-06T21:31:14.829+0300 writing config.cache.chunks.config.system.sessions to archive on stdout
    2020-05-06T21:31:14.832+0300 done dumping config.cache.chunks.config.system.sessions (1 document)
    2020-05-06T21:31:14.834+0300 writing config.cache.collections to archive on stdout
    2020-05-06T21:31:14.835+0300 done dumping config.cache.collections (1 document)
    2020/05/06 21:31:24 [##......................]   test.testt  130841/1073901  (12.2%)
    2020/05/06 21:31:24 [##########..............]  test.testt2   131370/300000  (43.8%)
    2020/05/06 21:31:24
    2020/05/06 21:31:34 [#####...................]   test.testt  249603/1073901  (23.2%)
    2020/05/06 21:31:34 [###################.....]  test.testt2   249603/300000  (83.2%)
    2020/05/06 21:31:34
    2020/05/06 21:31:37 [########################]  test.testt2  300000/300000  (100.0%)
    

pbm-agent logs

Version added: 1.4.0

To troubleshoot issues with specific events or node(s), use the pbm logs command. It provides logs of all pbm-agent processes in your environment.

pbm logs has the set of filters to refine logs for specific events like backup, restore, pitr or for a specific node, and to manage log verbosity level. For example, to view logs about a specific backup with the Debug verbosity level, run the pbm logs command as follows:

$ pbm logs --severity=D --event=backup/2020-10-15T17:42:54Z

To learn more about available filters and usage examples, refer to Viewing backup logs.

Get expert help

If you need assistance, visit the community forum for comprehensive and free database knowledge, or contact our Percona Database Experts for professional support and services.


Last update: December 21, 2023
Created: December 21, 2023