b87c397091
The current implementation of iobuf_pool has two problems: - prealloc of 12.5MB memory, this limits the scale factor of the gluster processes due to RAM requirements - lock contention, as the current implementation has one global iobuf_pool lock. Credits for debugging and addressing the same goes to Krutika Dhananjay <kdhananj@redhat.com>. Issue: #410 Hence changing the iobuf implementation to use per thread mem pool. This may theoritically appear to cause perf dip as there is no preallocation. But per thread mem pool will not have significant perf impact as the last allocated memory is kept alive for subsequent allocs, for some time. The worst case would be if iobufs requested are of random sizes each time. The best case is, if we get iobuf request of the same size. From the perf tests, this patch did not seem to cause any perf decrease. Note that, with this patch, the rdma performance is going to degrade drastically. In one of the previous patchsets we had fixes to not degrade rdma perf, but rdma is not supported and also not tested [1]. Hence the decision was to not have code in rdma that is not tested and not supported. [1] https://lists.gluster.org/pipermail/gluster-users.old/2018-July/034400.html Updates: #325 Change-Id: Ic2ef3bd498f9250dea25f25ba0c01fde19584b27 Signed-off-by: Poornima G <pgurusid@redhat.com>
Developer Guide
Gluster's contributors can check about the internals by visiting Developer Guide Section. While it is not 'comprehensive', it can help you to get started.
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Admin Guide
The gluster administration guide is maintained at github. The browsable admin guide can be found here.
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Features/Spec
The Gluster features which are 'in progress' or implemented can be found at github.
Upgrade Guide
The gluster upgrade guide is maintained at github. The browsable upgrade guide can be found here
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For more details about the docuemntation workflow please refer this discussion