EverData a leading data center and cloud solution provider in India has recently been writing quite a bit about Galera Cluster and it seems like we should highlight them. For one, they’ve talked about streaming replication in Galera Cluster 4, available in MariaDB Server 10.4. However, let us focus on their post: Galera Cluster vs Amazon RDS: A Comprehensive Review.
They compared MySQL with MHA, MySQL with Galera Cluster and also Amazon Web Services (AWS) Relational Database Service (RDS). Their evaluation criteria was to see how quickly there would be recovery after a crash, as well as performance while managing concurrent reads and writes.
In their tests, they found that time for failover with Galera Cluster between 8-10 seconds, whereas Aurora (so they were not using Amazon RDS?) took between 15-51 seconds, and MySQL with MHA took 140 seconds (which seems excessively high, considering this solution has been known to do sub-10 second failovers — so maybe needing some configuration tuning?)
In terms of performance, MySQL with MHA comes out the winner over Galera Cluster, but Galera Cluster comes out ahead of RDS (is this RDS MySQL or Aurora?). This can simply be explained that MySQL with MHA was likely configured with asynchronous replication and not semi-synchronous, and you’re only writing to one node as opposed to three nodes. (MHA setups recommend the use of semi-synchronous replication; also later on in the report, there is a note about replication lag).
Some takeaways in conclusion, straight from their report:
- “If HA and low failover time are the major factors, then MySQL with Galera is the right choice.”
- High Availability: “MySQL/Galera was more efficient and consistent, but the RDS didn’t justify the episodes of replication lags.”
- Performance: “MySQL/Galera outperformed the RDS in all tests — by the execution time, number of transactions, and rows managed.”
“we can see that MySQL/Galera manages the commit phase part more efficiently along with the replication and data validation.” Source: EverData
Looks extremely positive from a Galera Cluster standpoint, and we thank the team at EverData for such a report. It is interesting to read so take look Galera Cluster vs Amazon RDS: A Comprehensive Review.