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MongoDB: No host in new replica set maps to this node

In the “trivial-errors” category, I imagine one will encounter this error when setting up MongoDB replica sets.

What this means is that the current instance cannot connect to host 1 in my rsconfig for a few possible reasons. A firewall or network configuration blocking access to the MongoDB port. The host cannot be resolved. …

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Percona Replication Manager – Renaming Cluster Hostnames

Recently I’ve had to rename a node on a production cluster – however, I did not have an experience on this yet so I decided to try on a sandbox and establish a known procedure. Without further ado, assuming we have 3 nodes and we want to rename ha3’s hostname to ha03.

Here we …

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XtraBackup Complains of Missing perl-DBD-MySQL

I was busy testing a PXC cluster today when suddenly was buffled with a confusing error:

OK, so my first though was DBD::mysql is missing, but as I checked:

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 …

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Default RDS Account Privileges

I was searching looking for the PRIVILEGES that comes with the primary MySQL account on RDS, but it looks like this is not documented anywhere nor blogged about yet. So for the sake of other users, here it is:

In case you ask, for what, I was looking for what privileges I can grant …

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Zend_Paginator Without Adapter Data

If you simply want to take advantage of Zend_Paginators page generation function without feeding it actual data, how do you do it? Simple, implement Zend_Paginator_Adapter_Interface in your custom class and override three functions like below:

Then you can use it as you would the paginator class – the only parameter to the constructor is …

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Optimizing MIN and MAX MySQL Functions

MySQL can optimize aggregate functions like MIN and MAX as long as the columns specified are indexed. This means that, in the case of MIN and MAX, the optimizer should be able to identify the highest and lowest values of an indexed column from the B-Tree index. Say I have a table like below:

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Pacemaker Failed Actions ‘not installed’ And ‘not configured’

Playing around with Percona Replication Manager, and being new to Pacemaker, some errors were somewhat cryptic.

First, it says here that I have ‘operation monitor failed’ on node ha02.localdomain. This error simply means ‘I cannot run the operation monitor because it is not installed’. Where does this operation supposed to come from, from the …

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