Fixing Page Faults in MongoDB
Page faults are a prevalent error that mostly occurs in a large application involving large data. It takes place when MongoDB database reads data from physical memory rather than from virtual memory. Page fault errors...
Troubleshooting a MongoDB Sharded Cluster
In MongoDB, large data sets involve high throughput operations and this may overwhelm the capacity of a single server. Large working data sets implicate more stress on the I/O capacity of disk devices and may...
Eliminating PostgreSQL Split-Brain in Multi-Cloud Databases
Using a multi-cloud or multi-datacenter environment is useful for geo-distributed topologies or even for a disaster recovery plan, and actually, it is becoming more popular nowadays, therefore the concept of split-brain is also becoming more...
Eliminating MySQL Split-Brain in Multi-Cloud Databases
These days databases spanning across multiple clouds are quite common. They promise high availability and possibility to easily implement disaster recovery procedures. They are also a method to avoid vendor lock-in: if you design your...
How to Fix a Lock Wait Timeout Exceeded Error in MySQL
One of the most popular InnoDB errors is InnoDB lock wait timeout exceeded, for example: SQLSTATE[HY000]: General error: 1205 Lock wait timeout exceeded; try restarting transaction The above simply means the transaction has reached the...
How High CPU Utilization Effects Database Performance
One of the indicators to see if our database is experiencing performance issues is by looking at the CPU utilization. High CPU usage is directly proportional to disk I/O (where data is either read or...
How to Rebuild an Inconsistent MySQL Slave?
MySQL slaves may become inconsistent. You can try to avoid it, but it’s really hard. Setting super_read_only and using row-based replication can help a lot, but no matter what you do, it is still possible...
How to Rebuild an Inconsistent PostgreSQL Slave
PostgreSQL Streaming Replication is a great way of scaling PostgreSQL clusters and doing it adds high availability to them. As with every replication, the idea is that the slave is a copy of the master...
My PostgreSQL Database is Out of Disk Space
Disk space is a demanding resource nowadays. You usually will want to store data as long as possible, but this could be a problem if you don’t take the necessary actions to prevent a potential...
What to Check if MySQL Memory Utilisation is High
One of the key factors of a performant MySQL database server is having good memory allocation and utilization, especially when running it in a production environment. But how can you determine if the MySQL utilization...
What to Check if PostgreSQL Memory Utilization is High
Reading from memory will always be more performant than going to disk, so for all database technologies you would want to use as much memory as possible. If you are not sure about the configuration,...
Steps to Take if You Have a MySQL Outage
A MySQL outage simply means your MySQL service is not accessible or unresponsive from the other's perspective. Outages can be originated by a bunch of possible causes.. Network issue - Connectivity issue, switch, routing, resolver,...