2026d24667
Explicit invalidation by calling inode_invalidate is necessary when same (meta)data is shared/access across multiple mounts. Without an explicit inode_invalidate call, caches in the mount which didn't witness writes wouldn't be aware of changes as writes wouldn't have passed through them. 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, explicit inode 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. Note that otherwise, local writes (which pass through the cache) will change ctime and cause unnecessary invalidations. The name of the option that controls this behavior is "performance.global-cache-invalidation". This option is global and it purges caches both in glusterfs and kernel stack for native FUSE mounts. For non-native FUSE mounts, it purges cache only from glusterfs stack. This option is effective only when performance.stat-prefetch is on. Note that there is a similar option "performance.cache-invalidation", but the scope of that option is limited to quick-read and md-cache. Change-Id: I462bb4b65ff9aae1f6ba76f50b1f2f94fb10323b Signed-off-by: Raghavendra Gowdappa <rgowdapp@redhat.com> updates: bz#1674364 (cherry picked from commit 2b5aa4489de2017a03bcb6ec8986286f0c76a670)
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.