a229ee1c8c
Auto invalidation is necessary when same (meta)data is shared/access
across multiple mounts. However, if (meta)data is not shared, all
relevant I/O goes through the cache of single mount and hence is
coherent with (meta)data on bricks always. So, fuse-auto-invalidation
can be disabled for this case which gives a huge performance boost for
workloads that write data and then immediately read the data they just
wrote.
From glusterfs --help,
<snip>
--auto-invalidation[=BOOL] controls whether fuse-kernel can
auto-invalidate attribute, dentry and page-cache.
Disable this only if same files/directories are
not accessed across two different mounts
concurrently [default: "on"]
</snip>
Details on how disabling auto-invalidation helped to reduce pgbench
init times can be found at [1]. Time taken for pgbench init of scale
8000 was 8340s. That will be an improvement of 86% (59280s vs 8340s)
with auto-invalidations turned off along with other
optimizations. Just disabling auto-invalidation contributed 56%
improvement by reducing the total time taken by 33260s.
[1] https://www.spinics.net/lists/gluster-devel/msg25907.html
Change-Id: I0ed730dba9064bd9c576ad1800170a21e100e1ce
Signed-off-by: Raghavendra Gowdappa <rgowdapp@redhat.com>
updates: bz#1664934
Gluster
Gluster is a software defined distributed storage that can scale to several petabytes. It provides interfaces for object, block and file storage.
Development
Contributions to gluster in the form of patches and new feature additions can be made by following steps outlined at Developers Guide.
Documentation
The Gluster documentation can be found at Gluster Docs.
Deployment
Quick instructions to build and install can be found in INSTALL file.
Testing
GlusterFS source contains some functional tests under tests/ directory. All
these tests are run against every patch submitted for review. If you want your
patch to be tested, please add a .t test file as part of your patch submission.
You can also submit a patch to only add a .t file for the test case you are
aware of.
To run these tests, on your test-machine, just run ./run-tests.sh. Don't run
this on a machine where you have 'production' glusterfs is running, as it would
blindly kill all gluster processes in each runs.
If you are sending a patch, and want to validate one or few specific tests, then run a single test by running the below command.
bash# /bin/bash ${path_to_gluster}/tests/basic/rpc-coverage.t
You can also use prove tool if available in your machine, as follows.
bash# prove -vmfe '/bin/bash' ${path_to_gluster}/tests/basic/rpc-coverage.t
Maintainers
The list of Gluster maintainers is available in MAINTAINERS file.
License
Gluster is dual licensed under GPLV2 and LGPLV3+.
Please visit the Gluster Home Page to find out more about Gluster.