Note that unlike autotools, cmake tries to configure and build incrementally. You can modify one configuration option and cmake will only rebuild the part of the tree affected by it. For example, when you do cmake -DWITH_EMBEDDED_SERVER=1 in the already-built tree, it will make libmysqld to be built, but no other configuration options will be changed or reset to their default values.

In particular this means that if you have run, for examplecmake -DPLUGIN_OQGRAPH=NO and later you want to restore the default behavior (with OQGraph being built) in the same build tree, you would need to runcmake -DPLUGIN_OQGRAPH=DYNAMIC

Alternatively, you might simply delete the CMakeCache.txt file — this is the file where cmake stores current build configuration — and rebuild everything from scratch.

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If you are unsure which malloc implementation is in use, or if you used one of the procedures explained in this page and you want to verify if it succeeded, you can run this query:

A value of "system" indicates the system default, which is normally malloc. If another library is used, this query will return the name and version of the library.

Building MariaDB with an alternative to malloc

To build with TCMalloc, you need to use the following command

To use jemalloc, the option should be -ljemalloc.

Starting mariadbd-safe with an alternative to malloc

If you want to do this only one time, as a test, you can also start a standard MariaDB server with TCmalloc with:

If you want to configure mariadbd-safe to use tcmalloc or jemalloc, edit your configuration file, in the [mariadbd-safe] group:

Starting mariadbd with an alternative to malloc

First, locate the library file that needs to be used:

Now pass it to mariadbd using the LD_PRELOAD variable:

For example, on OpenSuse 15.4 one would do:

Configuring systemd

If you use systemd to run MariaDB, first locate the library as explained above. The locate the service configuration file:

Now edit the mariadb.service file by adding a line to the [Service] group:

For example:

Now you should reload the configuration, so that the news setting will take effect, and restart MariaDB:

Dockerfile

If you run MariaDB on Docker and use an image from a Dockerfile that is publicly available, most probably you have an entrypoint that is a Bash script, which starts mariadbd directly. You can edit this Bash script as explained above. Or you can set the LD_PRELOAD variable from the Dockerfile:

To find the library file you can run one of these commands while the container is running:

Example:

Vagrantfile

Usually Vagrant is used to start a complete system in a virtual machine. If this is your case, you can use one of the methods above, for example you can modify your Vagrantfile to copy a modified version of the mariadb.service file into the guest system to configure systemd.

If you use Vagrant with the Docker provider, you can follow the instructions above to modify the Dockerfile.

Finding memory leaks with jemalloc

jemalloc can provide a report of memory leaks at program exit:

This will produce something like:

You can learn more about the memory leaks with jeprof, that is included with jemalloc:

You can also generate a PDF call graph of the leak:

See Also

• Jemalloc leak checking

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