Category Archive For "Linux"
Testing ZFS vs ext4 with sysbench (Google Cloud)
I’ve had a chance to revisit ZFS lately and decided to take some more notes. One highlight of this test is revalidating a quick performance test against ext4. This test is ran on Google Compute Engine n1-highmem-8 (8 vCPU, 52GB RAM) with 2x375G local SSD attached via NVMe and 4x500G standard persistent disks using the …
Sandboxed MySQL Utilities – HowTo
Often I would need to work on customer servers where MySQL Utilities would be a really good fit for the tools I need. However, I would not want to mess around with the customer servers just to have it running so I would have the tools built and sandboxed on its own directory where I …
XtraBackup Complains of Missing perl-DBD-MySQL
I was busy testing a PXC cluster today when suddenly was buffled with a confusing error:
140108 23:33:39 innobackupex: Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup' (using password: NO).
innobackupex: Error: Failed to connect to MySQL server as DBD::mysql module is not installed at /usr/bin/innobackupex line 2913.
OK, so my first though was DBD::mysql is missing, but as I checked:
[root@pxc03 keepalived]# yum list installed| grep perl-DBD-MySQL
perl-DBD-MySQL.x86_64 4.013-3.el6 @base
After some digging, it’s not actually the module that is missing – it was one of the module’s dependency which is the mysql client …
Limit The Size of Your Core Files on Linux
So we all know that when troubleshooting MySQL crashes or any other processes in that regard, we simply enable core files to be dumped when the appropriate signal it triggered. To get the best results, we’d set the core file size limit everywhere to unlimited and be done with it, but what if you want …
MySQL Backups, The Tools So Far
Backups is one of the most important part of any MySQL deployment, and nowadays, there’s a number of tools to choose from depending on how your organization implements them. The purpose of this post is to enumerate the main tools and some helpers that makes backing up and testing/restoring your backups more convenient. By all …
Reduce Stack Frame Depth from XDebug Trace Output
Earlier, I’ve written about how to dump code trace from your PHP application using XDebug, however, more often that not, you get lengthy results and you simply want to get an overview up to certain depth. I’ve created a simple PHP for that which you can find here. It’s fairly easy to use, simply feed …
Check (Rough) Progress of Your CSV Import to MySQL
If you are importing large CSV or SQL dumps to MySQL, chances are you were looking for ways to see how far the import has gone. If you know how many rows there are from the file being imported, you can do a SELECT COUNT(*) but that would take sometime for the query to finish …