Category devops

CentOS 6 very slow with Vagrant

I use Vagrant to test almost everything. But since I upgraded to VirtuabBox 4.2.x and CentOS 6 as guess OS, I had the impression that everything was slower... and I get use to it... But this week-end while preparing selinux policies for Percona XtraDB Cluster, I noticed that it was really slow.... really really very very slooooow :'-( And I found the reason ! I first tried to add some kernel parameters like :
noacpi 
noapic 
divider=10 
notsc
But that didn't help. Then I just enabled IO APIC on the VM's configuration and it worked much faster ! The boot of the machine was faster and in my case loading selinux policies too ! Have a look to the difference: Without IO APIC:
[root@node2 ~]# time semodule -i percona-xtradb-cluster-full.pp

real	6m3.646s
user	1m34.430s
sys	3m42.805s
With IO APIC:
[root@node2 ~]# time semodule -i percona-xtradb-cluster-full.pp

real	0m14.611s
user	0m13.829s
sys	0m0.769s
To enable IO APIC from Vagrant, these are the parameters to use in your Vagrantfile:
config.vm.customize ["modifyvm", :id, "--memory", "256", "--ioapic", "on"]

MySQL facter

Yesterday I started to play with mcollective I added some agents like service and facter. I really liked the facter agent.... and then I decided to add facts for MySQL. Of course I needed to learn some ruby first :-) A fact is created for the version and all other MySQL facts come from the SHOW STATUS statement. All the new facts start by mysql_ I plan to add new facts related to the replication like Seconds_Behind_Master The current version is available on github here

Some usage examples:

with facter:
[root@delvaux facter]# facter mysql_version 2>/dev/null
5.5.10
[root@delvaux facter]# facter mysql_max_used_connections 2>/dev/null
3
with mcollective:
[root@delvaux facter]# mc-facts mysql_version
Report for fact: mysql_version

        5.0.51a-24+lenny5-log                   found 1 times
        5.5.10                                  found 1 times

Finished processing 2 / 2 hosts in 64.36 ms



[root@delvaux facter]# mc-facts mysql_open_files
Report for fact: mysql_open_files

        16                                      found 1 times
        18                                      found 1 times

Finished processing 2 / 2 hosts in 2418.13 ms

[root@delvaux facter]# mc-facts mysql_open_files -v
Determining the amount of hosts matching filter for 2 seconds .... 2
Report for fact: mysql_open_files

        16                                      found 1 times

            delvaux.maladree.be

        18                                      found 1 times

            debian1.maladree.be


---- rpc stats ----
           Nodes: 2 / 2
     Pass / Fail: 0 / 0
      Start Time: Sat Apr 02 00:11:46 +0200 2011
  Discovery Time: 2001.84ms
      Agent Time: 1344.24ms
      Total Time: 3346.08ms

[root@delvaux facter]# mc-facts mysql_threads_connected 
Report for fact: mysql_threads_connected

        2                                       found 2 times

Finished processing 2 / 2 hosts in 3270.86 ms

[root@delvaux facter]# mc-facts mysql_threads_connected -v
Determining the amount of hosts matching filter for 2 seconds .... 2
Report for fact: mysql_threads_connected

        2                                       found 2 times

            debian1.maladree.be
            delvaux.maladree.be


---- rpc stats ----
           Nodes: 2 / 2
     Pass / Fail: 0 / 0
      Start Time: Sat Apr 02 00:12:47 +0200 2011
  Discovery Time: 2001.73ms
      Agent Time: 50.43ms
      Total Time: 2052.15ms