Category Archives: CentOS / Red-Hat

CentOS/RHEL 6.4, Squid 3.1.10, IPV6 and TCP_MISS/503 errors

Since Squid 3.1.0, IPv6 support is “native” [1] and the following behavior occurs: The most active [IPv6 operation] will be DNS as IPv6 addresses are looked up for each website. Unfortunately, until Squid 3.1.16 which introduce the configuration parameter dns_v4_first [2], you cannot change Squid order for DNS queries and IPv6 AAAA queries will always [...]

RHEL 6.4: Pacemaker 1.1.8, adding CMAN Support (and getting rid of “the plugin”)

Since RHEL6.0, pacemaker is shipped as a technology preview (TP). As explained in a blog post[1] from The Cluster Guy, you could choose between different setup for membership and quorum data, actually, three options. But since RHEL 6.4 and Pacemaker 1.1.8, in an attempt to move towards what is best supported by Red-Hat (CMAN), you [...]

Monitor a Pacemaker Cluster with ocf:pacemaker:ClusterMon and/or external-agent

If you want to monitor your Pacemaker cluster status and get alerted in real time on any cluster transition, you must define an ocf:pacemaker:ClusterMon resource[1]. This resource must be cloned and will run on all nodes of the cluster. It works by using crm_mon[2] in the background, which is a binary that provides a summary [...]