no reload operation (graceful) apache pacemaker & corosync active/pasive cluster

[José Pedro]

Hi,
I've implemented a cluster (active/pasive) with apache in centos 7 using pacemaker & corosync. Everything related to the cluster operation is working fine.
The problem is that these apache is going to be also our load balancer. We need hi availability and the flexibility of the reload operation of the apache. On daily basis part of our tasks are to add sites, add nodes to the balanced applications, etc. So we need a cluster operation that permit us to invoke the apache reload (graceful) anytime we need without disrupt the service (user established connections, etc.)

We are using sevice ocf:apache, and these operations aren't available ..

Does anyone can help us with that?

Thanks in advance!
José Pedro

[1st Line Support]

Have you included the mod_status in your httpd.conf file? ocf_heartbeat_apache realise on it. And also check the mod_status.conf for it's settings, for your configuration

[José Pedro]

Hi,
First of all thanks you very much for your reply!! We are stagnant trying to resolve these issue since about a week.
Sorry but I’ve didn’t understand. Can you plase detail your explanation? You said that including these module the reload operation is going to be available from pcs? We need the availability to manual make changes to apache and invoke the reload (manualy two) without disrupt the service (user established connections, etc)
I have these line in httpd.conf:
Include conf.modules.d/*.conf, and in these directory there is “/conf.modules.d/00-base.conf” which includes:
LoadModule status_module modules/mod_status.so
So, I think the module is loaded but we haven’t got mod_status.conf file .. do you think we need to define it?

Tanks!!
Regards!
José Pedro

[José Pedro]

Hi,
perhaps my issue wasn’t explained clear. I’ll try to explain again:
We have cluster implementation working fine with two nodes and 2 services (configuration process resumed):
- Install the pacemaker and corosync.
- configuration with these commands (resume):
pcs resource create WebServer ocfapache configfile=/etc/httpd/conf/httpd.conf statusurl="http://127.0.0.1/server-status" op monitor interval=20s
pcs constraint colocation add WebServer ClusterVIP INFINITY
pcs constraint order ClusterVIP then WebServer
- and the cluster is working fine:
[root@lbcl01 ~]# pcs status
Cluster name: webcluster
Last updated: Wed Apr 27 01:51:41 2016 Last change: Mon Apr 18 03:38:50 2016 by root via crm_resource on lbcl01
Stack: corosync
Current DC: lbcl02 (version 1.1.13-10.el7_2.2-44eb2dd) - partition with quorum
2 nodes and 2 resources configured

Online: [ lbcl01 lbcl02 ]

Full list of resources:

ClusterVIP (ocf:IPaddr2): Started lbcl01
WebServer (ocf:apache): Started lbcl01

PCSD Status:
lbcl01: Online
lbcl02: Online

Daemon Status:
corosync: active/enabled
pacemaker: active/enabled
pcsd: active/enabled

The apache service is going to be a 7x24 load balancer and here is my problem:
Normally Every day we modify load balancer configuration, by example:
- Add new nodes to a balanced url, webservice, etc
- Modify nodes and urls
- Etc .. etc .. etc
So we need that the load balancer configuration can be reload gracefuly (without downtime). But the only operation that we can invoke is restart (pcs resource restart WebServer) … but restart implies apache stop+start and this is going to be very disruptive for own users an unacceptable.
In the previos versions (init) we resolve these invoking /etc/init.d/httpd graceful …. And these works fine … but now we could’t invoke apache operations directly …

So the question is:
How can we have a full configuration reload of the apache without disrupting users work??
Thanks you very much!!
José Pedro

[Floro del Monte]

Hi Jose Pedro! Same issue, i dont know how reload the apache configuration. Did you solve it?

Regards

[José Pedro]

Hi Floro,
No, unfortunately no, and I’ve doesn’t receive any feedback. 
1st line support answered me with a question asking about if I’ve implemented mod_status (what is evident because you need it, in order to have apache working on 2 nodes cluster … ) but after that … no more news…. Perhaps now (with your company) we have more lucky …

Thanks, regards!
José Pedro

[teeheelaryn]

Hi everyone,

Have you found out already a way to reload the config?

Thanks!

[José Pedro]

Hi,
no, isn't implemented yet, and can't obtain a convincent answer . Can you?

thanks!

[micsto]

Hi ,
i my pacemaker enviroment i do a kill -USR1 `cat /var/run/httpd.pid`

[JamesStevensIT]

Has anyone resolved this yet?