SST XtraDB Backup - Use a different tmp directory

MySQL & MariaDB Percona XtraDB Cluster 5.x
1

Hi all,

Our current tmp directory is only 5GB and it’s not able to perform SST backup as the tmp directory gets filled up really quickly.

Setting tmpdir under [mysqld] or [xtrabackup] doesn’t work for me. I have also checked the permissions. It is still using /tmp for the SST.

We are using the following version:

Server version: 5.7.16-10-57-log Percona XtraDB Cluster (GPL), Release rel10, Revision bec0879, WSREP version 27.19, wsrep_27.19

Any ideas please?

Thanks!

2

Currently, in PXC 5.7, the tmpdir parameter doesn’t do very much for xtrabackup-v2 SST (changes the location of some temporary files used by the script)

To change the location of the backup files, as a workaround, you can manually edit the wsrep_sst_xtrabackup-v2 script

change the line (around line 1127)
itmpdir=$(mktemp -d)
to
itmpdir=/path/to/your/temp/file

3

Thanks, that works!

4

Hi,
another option set the TMPDIR on the top of the script:

edit wsrep_sst_xtrabackup-v2 and add

export TMPDIR=/mysql/sst_ist_stage

later, you will se the change on the script:

WSREP_SST: [INFO] Streaming with xbstream (20170323 16:11:51.102)
WSREP_SST: [INFO] Using socat as streamer (20170323 16:11:51.105)
WSREP_SST: [INFO] Using /mysql/sst_ist_stage/tmp.LxzmCD7EUA as xtrabackup temporary directory (20170323 16:11:51.126)
WSREP_SST: [INFO] Using /mysql/sst_ist_stage/tmp.yPp4ONZAvD as innobackupex temporary directory (20170323 16:11:51.130)

thanks,
regards
Mariano

5

The fixes for this has just been released for PXC 5.6 and 5.7:

[url]https://www.percona.com/blog/2017/04/19/percona-xtradb-cluster-5-6-35-26-20-3-now-available/[/url]
[url]https://www.percona.com/blog/2017/04/19/percona-xtradb-cluster-5-7-17-29-20-now-available/[/url]

PXC will now check for and use the tmpdir option.

6

I think you have to set the tmpdir in the sst section in the .cnf file
[sst]
tmpdir=/location