MariaDB vs. MySQL 8.0: Performance Benchmarks & Configuration Guide for VPS

It’s Not About Philosophy, It’s About RAM

In the open-source community, the debate between MariaDB and MySQL often devolves into arguments about Oracle’s corporate ownership versus open-source purity. At ServerSpan, we don't pick software based on ideology; we pick it based on what wakes us up at 3 AM the least. In our experience managing thousands of Linux VPS instances, the technical divergence between these two databases has become significant enough that "drop-in replacement" is no longer a 100% accurate statement.

When we provision a new Managed VPS, we default to MariaDB for a specific reason: resource efficiency on constrained hardware. However, MySQL 8.0 has features that enterprise-grade applications specifically require. This guide breaks down the configuration differences that actually impact your VPS Performance, ignoring the fluff.

1. The Connection Handling Gap: Thread Pool

The Theory:
This is the single biggest differentiator for high-traffic sites. Standard MySQL Community Edition uses a "one-thread-per-connection" model. If you have 500 concurrent users, MySQL spawns 500 threads. This creates massive context-switching overhead for the CPU. MariaDB includes a "Thread Pool" (similar to Nginx’s worker model) that keeps a fixed number of threads active and queues the requests.

The Implementation:
On a High Performance VPS running MariaDB, we explicitly enable this in `/etc/mysql/mariadb.conf.d/50-server.cnf` if it isn't on by default (it usually depends on the version):

[mysqld]
thread_handling = pool-of-threads
thread_pool_size = 16  # Matches CPU core count usually

The Edge Case:
Long-running queries. If a bad query locks a thread in the pool for 10 seconds, it blocks other fast queries. We configure `thread_pool_stall_limit` to prevent a single reporting query from taking down the checkout process.

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2. Memory Footprint: MySQL 8 is Hungry

The Theory:
MySQL 8.0 introduced a significant refactoring of the data dictionary. While architecturally sound, it resulted in a much higher base memory requirement. We have observed that a blank MySQL 8 instance idles at roughly 400-500MB of RAM, whereas MariaDB 10.11 idles closer to 150MB.

The Implementation:
If you are on a Cheap VPS with 2GB of RAM or less, we strongly recommend MariaDB. If you must use MySQL 8, you have to be aggressive with your `innodb_buffer_pool_size` and disable performance schema if you aren't using it.

# For MySQL 8 on low-RAM VPS
performance_schema = OFF
innodb_buffer_pool_size = 512M

The Edge Case:
The OOM Killer. We frequently see VPS Server logs where the kernel kills MySQL 8 during a backup because the memory footprint spiked slightly. MariaDB's leaner profile provides a wider safety buffer on small instances.

3. Replication and Clustering: Galera vs. Group Replication

The Theory:
When a client asks for "High Availability," they mean they want a cluster. MariaDB utilizes Galera Cluster (multi-master) natively. It is battle-tested and synchronizes nodes virtually instantly. MySQL has "InnoDB Cluster" (Group Replication), which is robust but significantly more complex to configure and manage for the average sysadmin.

The Implementation:
Bootstrapping a Galera cluster on MariaDB involves editing `wsrep_` settings. It allows us to set up a 3-node Cloud VPS cluster where you can write to any node.

The Edge Case:
Network latency. Galera is synchronous. If one of your nodes is in New York and another is in Frankfurt, the write speed is limited by the ping time (latency) between them. We always deploy clusters within the same datacenter or region to avoid stalling the application.

4. JSON Support: The Compatibility Trap

The Theory:
This is where "drop-in replacement" fails. MySQL 5.7+ introduced a native JSON data type. MariaDB stores JSON as `LONGTEXT` with constraint checks. While both support functions like `JSON_EXTRACT`, the syntax has diverged. MySQL has functions like `JSON_TABLE` that MariaDB implemented differently or later.

The Implementation:
If you are migrating a Laravel application or specialized app from a Self Hosted VPS running MySQL to MariaDB, check your raw SQL queries.

-- MySQL Syntax
SELECT col->"$.key" FROM table;

-- MariaDB Syntax (Compatible, but sometimes stricter)
SELECT JSON_UNQUOTE(JSON_EXTRACT(col, "$.key")) FROM table;

The Edge Case:
We migrated a client using a specialized WordPress plugin for inventory management that relied on a specific MySQL 8.0 JSON function unavailable in MariaDB 10.6. The site threw 500 errors. We had to specifically upgrade MariaDB to the latest version (11.x) to get better compatibility, but the risk remains.

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5. Storage Engines: It's Not Just InnoDB

The Theory:
MySQL is effectively InnoDB-only these days (MyISAM is dead). MariaDB, however, ships with alternative engines like MyRocks (optimized for flash storage compression) and Aria (a crash-safe replacement for temporary tables). For a VPS for Developers experimenting with big data, MariaDB offers more toys.

The Implementation:
We rarely change the default engine for main tables, but we do optimize temporary tables. MariaDB uses Aria for internal temporary tables on disk, which is faster than MyISAM.

The Edge Case:
Full-text search. If you are relying on database-level full-text search (instead of Elasticsearch), the implementation differs slightly in performance. We generally recommend offloading search to a dedicated service rather than asking the database to do heavy text parsing.

6. The Upgrade Path: mysql_upgrade is dead

The Theory:
In the past, after upgrading binaries, we ran `mysql_upgrade`. In MySQL 8.0, this is done automatically by the binary. MariaDB still relies on `mariadb-upgrade` (formerly `mysql_upgrade`) in many contexts to fix permission tables.

The Implementation:
When performing VPS Management and system updates (`apt upgrade`), if the database version bumps, we always check the logs.

# For MariaDB updates
mariadb-upgrade --force -u root -p

The Edge Case:
If you skip this step, we often see "Table 'performance_schema...' doesn't exist" errors filling up the logs, consuming VPS Storage.

Final Thoughts from the Ops Team

So, which one do we choose? For 90% of our Managed Cloud VPS deployments, we choose MariaDB. It is lighter, the thread pool saves us from traffic spikes, and the default configuration is more sensible for the web.

However, if your developers demand specific MySQL 8 JSON features or you are using Oracle-specific enterprise tools, stick to MySQL. Just be prepared to allocate 20-30% more RAM to get the same throughput. If you are unsure which engine fits your workload, open a ticket with us. We can look at your schema and give you a pragmatic answer, not a philosophical one.