Re: [druid-user] java.lang.OutOfMemoryError: Map failed

Running OOM from an mmap process means that you have very little off-heap memory space available. How much off-heap is available when the task is running?

Rommel Garcia

Have you checked the JVM settings for your middle manager processes?

This might help explain how memory is used. How many middle managers do you have and how are they each configured in terms of druid.worker.capacity?


How are your ingestion tasks configured? Are the maxRows and handoffperiod configured properly?

I would start with those pages and make sure that the the math makes sense for your environment.

Following Rommel and Rachel - just a note that there is work to better estimate required heap memory when constructing a Thetasketch (as you are doing) - if it were me for now I would increase heap sizes as per their notes.

Also, I note that Query Granularity is set to one hour - I wonder if the metrics processing part is having to consume too many rows? Ie it’s trying to output a sketch and all your metrics for each eventName and action on that hour. Have you tried reducing it to, say, MINUTE?