Cannot mlockall because JNA is not available – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch is unable to lock the process’s address space into RAM, due to the Java Native Access (JNA) library not being available. This can lead to swapping and degrade Elasticsearch performance. To resolve this issue, ensure that the JNA library is installed and available to Elasticsearch. If it’s already installed, check the library’s permissions and the Elasticsearch user’s permissions. Alternatively, you can disable memory swapping in Elasticsearch, but this could potentially lead to out-of-memory errors.

This guide will help you check for common problems that cause the log ” cannot mlockall because JNA is not available ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: bootstrap.

Log Context

Log “cannot mlockall because JNA is not available” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        JNA_AVAILABLE = v;

    static void tryMlockall() {
        if (JNA_AVAILABLE == false) {
            logger.warn("cannot mlockall because JNA is not available");


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