* When a writev call occurs, the client compresses the data before sending it to server. On the server, compressed data is decompressed. Similarly, when a readv call occurs, the server compresses the data before sending it to client. On the client, the compressed data is decompressed. Thus the amount of data sent over the wire is minimized. * Compression/Decompression is done using Zlib library. * During normal operation, this is the format of data sent over wire : <compressed-data> + trailer(8) The trailer contains the CRC32 checksum and length of original uncompressed data. This is used for validation. HOW TO USE ---------- Turning on compression xlator: gluster volume set <vol_name> compress on Configurable options: gluster volume set <vol_name> compress.compression-level 8 gluster volume set <vol_name> compress.min-size 50 Change-Id: Ib7a66b6f1f70fe002b7c513588cdf75c69370805 BUG: 923540 Original-author : Venky Shankar <vshankar@redhat.com> Signed-off-by: Venky Shankar <vshankar@redhat.com> Signed-off-by: Prashanth Pai <nullpai@gmail.com> Signed-off-by: Prashanth Pai <ppai@redhat.com> Reviewed-on: http://review.gluster.org/3251 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Vijay Bellur <vbellur@redhat.com>
The current coroutine model, mapping synctasks 1-1 with qemu internal Coroutines, has some unresolved raciness issues. This problem usually manifests as lifecycle mismatches between top-level (gluster created) synctasks and the subsequently created internal coroutines from that context. Qemu's internal queueing (and locking) can cause situations where the top-level synctask is destroyed before the internal scheduler has released references to memory, leading to use after free crashes and asserts. Simplify the coroutine model to use a single synctask as a coroutine processor and rely on the existing native ucontext coroutine implementation. The syncenv thread is donated to qemu and ensures a single top-level coroutine is processed at a time. Qemu now has complete control over coroutine scheduling. BUG: 986775 Change-Id: I38223479a608d80353128e390f243933fc946fd6 Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-on: http://review.gluster.org/6110 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
Add basic backing image support to the block-format mechanism. This is a functionality checkpoint that enables the raw mechanism required to support client driven "snapshot" and "clone" requests. This change enhances the block-format setxattr command to support an additional and optional backing image reference. For example: setxattr -n trusted.glusterfs.block-format -v "qcow2:10GB:<bimg>" ./newimage ... where <bimg> refers to the backing image for unallocated blocks in newimage. <bimg> can be provided in one of two formats: - a gfid string in the following format (assuming a valid gfid): <gfid:00000000-0000-0000-0000-000000000000> - or a filename that must be resident in the same directory as the new clone file being formatted. E.g., setxattr -n trusted.glusterfs.block-format -v "qcow2:10GB:baseimg" ./newimage This latter format is more restrictive, simply provided for convenience or until something more refined is available. This change makes no assumptions about the backing image file and affords no additional protection. It is up to the user/client to recognize the relationship between the files and manage them appropriately (i.e., no writes to the backing image, etc.). BUG: 986775 Change-Id: I7aff7bdc59b85a6459001a6bfeae4db6bf74f703 Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-on: http://review.gluster.org/5967 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
Add support for a new ZEROFILL fop. Zerofill writes zeroes to a file in
the specified range. This fop will be useful when a whole file needs to
be initialized with zero (could be useful for zero filled VM disk image
provisioning or during scrubbing of VM disk images).
Client/application can issue this FOP for zeroing out. Gluster server
will zero out required range of bytes ie server offloaded zeroing. In
the absence of this fop, client/application has to repetitively issue
write (zero) fop to the server, which is very inefficient method because
of the overheads involved in RPC calls and acknowledgements.
WRITESAME is a SCSI T10 command that takes a block of data as input and
writes the same data to other blocks and this write is handled
completely within the storage and hence is known as offload . Linux ,now
has support for SCSI WRITESAME command which is exposed to the user in
the form of BLKZEROOUT ioctl. BD Xlator can exploit BLKZEROOUT ioctl to
implement this fop. Thus zeroing out operations can be completely
offloaded to the storage device , making it highly efficient.
The fop takes two arguments offset and size. It zeroes out 'size' number
of bytes in an opened file starting from 'offset' position.
This patch adds zerofill support to the following areas:
- libglusterfs
- io-stats
- performance/md-cache,open-behind
- quota
- cluster/afr,dht,stripe
- rpc/xdr
- protocol/client,server
- io-threads
- marker
- storage/posix
- libgfapi
Client applications can exloit this fop by using glfs_zerofill introduced in
libgfapi.FUSE support to this fop has not been added as there is no system call
for this fop.
Changes from previous version 3:
* Removed redundant memory failure log messages
Changes from previous version 2:
* Rebased and fixed build error
Changes from previous version 1:
* Rebased for latest master
TODO :
* Add zerofill support to trace xlator
* Expose zerofill capability as part of gluster volume info
Here is a performance comparison of server offloaded zeofill vs zeroing
out using repeated writes.
[root@llmvm02 remote]# time ./offloaded aakash-test log 20
real 3m34.155s
user 0m0.018s
sys 0m0.040s
[root@llmvm02 remote]# time ./manually aakash-test log 20
real 4m23.043s
user 0m2.197s
sys 0m14.457s
[root@llmvm02 remote]# time ./offloaded aakash-test log 25;
real 4m28.363s
user 0m0.021s
sys 0m0.025s
[root@llmvm02 remote]# time ./manually aakash-test log 25
real 5m34.278s
user 0m2.957s
sys 0m18.808s
The argument log is a file which we want to set for logging purpose and
the third argument is size in GB .
As we can see there is a performance improvement of around 20% with this
fop.
Change-Id: I081159f5f7edde0ddb78169fb4c21c776ec91a18
BUG: 1028673
Signed-off-by: Aakash Lal Das <aakash@linux.vnet.ibm.com>
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
remove server_ctx and locks_ctx from client_ctx directly and store as into discrete entities in the scratch_ctx hooking up dump will be in phase 3 BUG: 849630 Change-Id: I94cea328326db236cdfdf306cb381e4d58f58d4c Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com> Reviewed-on: http://review.gluster.org/5678 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
Change-Id: Ic3f9d30d75df0bbbdf8fe28446fabe62d90fa854 BUG: 1024666 Signed-off-by: Pranith Kumar K <pkarampu@redhat.com> Reviewed-on: http://review.gluster.org/6194 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Amar Tumballi <amarts@redhat.com> Reviewed-by: Vijay Bellur <vbellur@redhat.com>
gettimeofday() returns the current wall clock time and timezone. Using these functions in order to measure the passage of time (how long an operation took) therefore seems like a no-brainer. This time suffer's from some limitations: a. They have a low resolution: “High-performance” timing by definition, requires clock resolutions into the microseconds or better. b. They can jump forwards and backwards in time: Computer clocks all tick at slightly different rates, which causes the time to drift. Most systems have NTP enabled which periodically adjusts the system clock to keep them in sync with “actual” time. The adjustment can cause the clock to suddenly jump forward (artificially inflating your timing numbers) or jump backwards (causing your timing calculations to go negative or hugely positive). In such cases timer thread could go into an infinite loop. From 'man gettimeofday': ---------- .. .. The time returned by gettimeofday() is affected by discontinuous jumps in the system time (e.g., if the system administrator manually changes the system time). If you need a monotonically increasing clock, see clock_gettime(2). .. .. ---------- Rationale: For calculating interval timing for Timer thread, all that’s needed should be clock as a simple counter that increments at a stable rate. This is necessary to avoid the jumps which are caused by using "wall time", this counter must be monotonic that can never “tick” backwards, ever. Change-Id: I701d31e71a85a73d21a6c5cd15583e7a5a645eeb BUG: 1017993 Signed-off-by: Harshavardhana <harsha@harshavardhana.net> Reviewed-on: http://review.gluster.org/6070 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
Currently to know the number of files to be healed, either user
has to go to backend and check the number of entries present in
indices/xattrop directory. But if a volume consists of large
number of bricks, going to each backend and counting the number
of entries is a time-taking task. Otherwise user can give
gluster volume heal vol-name info command but with this
approach if no. of entries are very hugh in the indices/
xattrop directory, it will comsume time.
So as a feature, new command is implemented.
Command 1: gluster volume heal vn statistics heal-count
This command will get the number of entries present in
every brick of a volume. The output displays only entries
count.
Command 2: gluster volume heal vn statistics heal-count
replica 192.168.122.1:/home/user/brickname
Here if we are concerned with just one replica.
So providing any one of the brick of a replica will get
the number of entries to be healed for that replica only.
Example:
Replicate volume with replica count 2.
Backend status:
--------------
[root@dhcp-0-17 xattrop]# ls -lia | wc -l
1918
NOTE: Out of 1918, 2 entries are <xattrop-gfid> dummy
entries so actual no. of entries to be healed are
1916.
[root@dhcp-0-17 xattrop]# pwd
/home/user/2ty/.glusterfs/indices/xattrop
Command output:
--------------
Gathering count of entries to be healed on volume volume3 has been successful
Brick 192.168.122.1:/home/user/22iu
Status: Brick is Not connected
Entries count is not available
Brick 192.168.122.1:/home/user/2ty
Number of entries: 1916
Change-Id: I72452f3de50502dc898076ec74d434d9e77fd290
BUG: 1015990
Signed-off-by: Venkatesh Somyajulu <vsomyaju@redhat.com>
Reviewed-on: http://review.gluster.org/6044
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>
bdrv_init() is intended to be invoked only once. If invoked again after initialization (i.e., due to graph changes), the block driver registration code can reinsert entries into bdrv_drivers, effectively corrupting the NULL terminated linked list. This manifests as an infinite loop for callers attempt to traverse the list (to locate a driver). BUG: 986775 Change-Id: I2f95bda3c753dece4648cdad009d0e2a2d16f644 Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-on: http://review.gluster.org/6021 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>
change in encoding method of changelog was critical section for "fop dispatch thread", "roll-over thread" and "reconfigure dispatch thread". In this patch the "encoding-method" is changed by the reconfigure dispatch thread lazily during handle_change, which solves the concurrency among the racing threads. BUG: 1002940 Change-Id: I78c3e8887efa46d0fcc60755cdf4243031cfa3eb Signed-off-by: Ajeet Jha <ajha@redhat.com> Reviewed-on: http://review.gluster.org/5844 Reviewed-by: Venky Shankar <vshankar@redhat.com> Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Harshavardhana <harsha@harshavardhana.net>