https://carl.duevel.online/tags/memory/ Recent content in Memory on Personal weblog Hugo en Sat, 22 Jan 2022 18:30:50 +0100 https://carl.duevel.online/blog/max_ram_percentage/ Sat, 22 Jan 2022 18:30:50 +0100 https://carl.duevel.online/blog/max_ram_percentage/ <p> The other day at work a Clojure program on a machine with 100 GB ran into OutOfMemory errors. A quick look at the metrics showed that the heap was only at about 30 GB though. Checking the JVM flags I found a configuration that is commonplace:</p> <div class="src src-bash"> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-bash" data-lang="bash"><span class="line"><span class="cl">-XX:MaxRAMPercentage<span class="o">=</span><span class="m">80</span></span></span></code></pre></div> </div> <p>So one would assume that the JVM could have sized the heap much larger than it actually did. Thanks to docker this behavior can be observed quite easily by doing a few tests like this one:</p>