Percona logical backup slower than mongodump

MongoDB Percona Backup for MongoDB
1

Hi,

I have a MongoDB (community version) with size 484GB.
I try to test backup by percona and mongodump:
Percona:

  • type: logical
  • compress: gzip
  • total time to backup: 19 hours
  • output size: 207GB
    Mongodump:
  • compress: gzip
  • total time to backup: 15 hours.
  • output size: 207 GB

How to optimize Logical Backup in Percona ?
Thank in advanced,

2

Hi @Truong_Ha ,
Thanks for asking and trying out PBM!
Can you share more details on your MongoDB setup? Is that a standalone server, shared, or replica set? What storage do you use underneath?

3

Hi Radoslaw,

I use standalone server. Storage is SAN.

4

OK. So, for the standalone, the backup’s performance should be comparable.

Disk performance might vary. Can you conduct the test again and provide disk performance over time (IOPS, latency, read/write speed)?

5

Ok, i will test again and report results,

Thank in advance,

6

Awesome! Looking forward!

7

In the meantime, my friend @Ivan_Groenewold has found out that mongodump by default exports four collections in parallel (https://www.mongodb.com/docs/database-tools/mongodump/#std-option-mongodump.--numParallelCollections), whereas PBM does 50% of CPU cores, so it works more reliably on smaller machines. If your host has only 4 CPU cores, then maybe this explains the longer time. You can also compare CPU utilization between those two tools.

8

Can Percona config or modify num parallel to backup ?

9

I tested again, but total backup time is still the same, about 18hours.

I also tried upgrading CPU, RAM from 8CPU, 8GB RAM to 16 CPU, 16GB RAM, but the logical backup time result is still the same, about 18hours.

1 Like
10

Thanks @Truong_Ha - We’ll try to improve performance in the next iteration we’ll be working on in September. When I have some more news, I’ll let you know.

Again, thanks for bringing this topic into our attention.