Hi all, I would like to propose bundling jemalloc as a new dependency under `3rdparty/`, and to link Mesos against this new memory allocator by default.
# Motivation The Mesos master and agent binaries are, ideally, very long-running processes. This makes them susceptible to memory issues, because even small leaks have a chance to build up over time to the point where they become problematic. We have seen several such issues on our internal Mesos installations, for example https://issues.apache.org/jira/browse/MESOS-7748 or https://issues.apache.org/jira/browse/MESOS-7800. I imagine any organization running Mesos for an extended period of time has had its share of similar issues, so I expect this proposal to be useful for the whole community. # Why jemalloc? Given that memory issues tend to be most visible after a given process has been running for a long time, it would be great to have the option to enable heap tracking and profiling at runtime, without having to restart the process. (This ability could then be connected to a Mesos endpoint, similar to how we can adjust the log level at runtime) The two production-quality memory allocators that have this ability currently seem to be tcmalloc and jemalloc. Of these, jemalloc does produce in our experience better and more detailed statistics. # What is the impact on users who do not need this feature? Naturally, not every single user of Mesos will have a need for this feature. To ensure these users would not experience serious performance regressions as a result of this change, we conducted a preliminary set of benchmarks whose results are collected under https://issues.apache.org/jira/browse/MESOS-7876 It turns out that we could probably even expect a small speedup (1% - 5%) as a nice side-effect of this change. Users who compile Mesos themselves would of course have the option to disable jemalloc at configuration time or replace it with their memory allocator of choice. I'm looking forward to hear any thoughts and comments. Thanks, -- Benno Evers Software Engineer, Mesosphere
