glusterfs-snapshot.git/xlators/features/marker, branch development

glusterfs: zerofill support

2013-11-11T05:25:49+00:00

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 
Signed-off-by: M. Mohan Kumar 
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

features/marker: force xtime updates (configurable) for client-pid = -1

2013-09-05T03:43:03+00:00

This is required by Geo-Replication that does auxillary mount
with client-pid as -1 (which has special treatment at specific
places in GlusterFS), to trigger xtime updates on the intermediate
master in a cascading setup.

Marker too had a check to "not" mark updates for geo-replication's
auxillary mounts. With the new geo-replication design, xtimes are
not set by the master on the slave for all entities. Due to this
cascading setups were broken.

This patch introduces "geo-replication.ignore-pid-check" option
as a "override" for the client-pid check for gsyncd's client-pid.
When this options is enabled, marker start "marking" even if the
updates are from the special client.

Geo-Replication on the detection of itself being an intermediate
master, enables this option.

Change-Id: I9f7140edd12fef5480595ee0f93f35b94cdb8345
BUG: 996371
Signed-off-by: Venky Shankar 
Reviewed-on: http://review.gluster.org/5591
Tested-by: Gluster Build System 
Reviewed-by: Avra Sengupta 
Tested-by: Avra Sengupta 
Reviewed-by: Anand Avati

features/marker: pass xdata in marker_unlink()

2013-07-24T17:41:30+00:00

Change-Id: Ia310af96b25f29351f3adc4bbc97aea271df7673
BUG: 987747
Signed-off-by: Venky Shankar 
Reviewed-on: http://review.gluster.org/5379
Reviewed-by: Amar Tumballi 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

move 'xlators/marker/utils/' to 'geo-replication/' directory

2013-07-22T08:53:03+00:00

Change-Id: Ibd0faefecc15b6713eda28bc96794ae58aff45aa
BUG: 847839
Original Author: Amar Tumballi 
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/5133
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

features/changelog: changelog translator

2013-07-22T08:52:24+00:00

This is the initial version of the Changelog Translator.

What is it
-----------
Goal is to capture changes performed on a GlusterFS volume.
The translator needs to be loaded on the server (bricks) and
captures changes in a plain text file inside a configured
directory path (controlled by "changelog-dir", should be
somewhere in /.glusterfs/changelog by default).

Changes are classified into 3 types:
    - Data:     : TYPE-I
    - Metadata  : TYPE-II
    - Entry     : TYPE-III

Changelog file is rolled over after a certain time interval
(defauls to 60 seconds) after which a changelog is started.
The thing to be noted here is that for a time interval
(time slice) multiple changes for an inode are recorded only
once (ie. say for 100+ writes on an inode that happens within
the time slice has only a single corresponding entry in the
changelog file). That way we do not bloat up the changelog
and also save lots of writes.

Changelog Format
-----------------
TYPE-I and TYPE-II changes have the gfid on the entity on
which the operation happened. TYPE-III being a entry op
requires the parent gfid and the basename. Changelog format
has been kept to a minimal and it's upto the consumers to
do the heavy loading of figuring out deletes, renames etc..
A single changelog file records all three types of changes,
with each change starting with an identifier ("D": DATA,
"M": METADATA and "E": ENTRY). Option is provided for the
encoding type (See TUNABLES).

Consumers
----------
The only consumer as of today would be geo-replication, although
backup utilities, self-heal, bit-rot detection could be possible
consumers in the future.

CLI
----
By default, change-logging is disabled (the translator is present
in the server graph but does nothing). When enabled (via cli) each
brick starts to log the changes. There are a set of tunable that
can be used to change the translators behaviour:

- enable/disable changelog (disabled by default)
  gluster volume set  changelog {on|off}

- set the logging directory (/.glusterfs/changelogs is the
  default)
  gluster volume set  changelog-dir /path/to/dir

- select encoding type (binary (default) or ascii)
  gluster volume set  encoding {binary|ascii}

- change the rollover time for the logs (60 secs by default)
  gluster volume set  rollover-time 

- when secs > 0, changelog file is not open()'d with O_SYNC flag
- and fsync is trigerred periodically every  seconds.
  gluster volume set  fsync-interval 

features/changelog: changelog consumer library (libgfchangelog)

A shared library is provided for the consumer of the changelogs
for easy acess via APIs. Application can link against this library
and request for changelog updates. Conversion of binary logs to
human-readable ascii format is also taken care by the library which
keeps a copy of the changelog in application provided working
directory.

Change-Id: I75575fb7f1c53d2bec3dba1a329ea7bb3c628497
BUG: 847839
Original Author: Venky Shankar 
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/5127
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterfs: discard (hole punch) support

2013-06-13T21:37:43+00:00

Add support for the DISCARD file operation. Discard punches a hole
in a file in the provided range. Block de-allocation is implemented
via fallocate() (as requested via fuse and passed on to the brick
fs) but a separate fop is created within gluster to emphasize the
fact that discard changes file data (the discarded region is
replaced with zeroes) and must invalidate caches where appropriate.

BUG: 963678
Change-Id: I34633a0bfff2187afeab4292a15f3cc9adf261af
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/5090
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

gluster: add fallocate fop support

2013-06-13T21:37:21+00:00

Implement support for the fallocate file operation. fallocate
allocates blocks for a particular inode such that future writes
to the associated region of the file are guaranteed not to fail
with ENOSPC.

This patch adds fallocate support to the following areas:

	- libglusterfs
	- mount/fuse
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

BUG: 949242
Change-Id: Ice8e61351f9d6115c5df68768bc844abbf0ce8bd
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/4969
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

gsync: Display additional information in status command

2013-04-04T08:04:19+00:00

Added code to display extra information when status command
is executed.
 Information shown now are
1 Number of files synced
2 crawl time
3 total sync time
4 bytes synced

bytes synced is taken from rsync output .
--stats option of rsync gives extra infor
mation about the sync.In stats output there
is a field called Total transferred file
size which states the ammount of bytes synced .
This information is parsed from stdout output
using regular expressions.Bytes synced information
can be used to calculate throughput.

Change-Id: Id9bba9fff45ee7049bb8257c6fd918e5237e05b1
BUG: 947774
Signed-off-by: sarvotham s pai 
Reviewed-on: http://review.gluster.org/4749
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

features/marker: log error when unlinking timestamp file

2013-03-21T11:21:45+00:00

... so it's easy to figure out errno caused it. As of now
it's only due to ENOSPC. Logging is done in the error handling
routine, so any further changes that require unlinking of the
timestamp file due to some error condition(s) are logged.

Change-Id: Ia59338e2e32b2adbbd1d56aa260018270f1abae9
BUG: 853911
Signed-off-by: Venky Shankar 
Reviewed-on: http://review.gluster.org/4649
Reviewed-by: Csaba Henk 
Reviewed-by: Amar Tumballi 
Reviewed-by: Vijay Bellur 
Tested-by: Gluster Build System

geo-rep: retire old style ssh setup

2013-03-14T07:23:23+00:00

Users are still using geo-rep with the old, deprecated, insecure, unsupported
ssh setup. Not their fault -- the implementation of the new method had the
following charasteristics:
- old method is possible, but with default settings it's not working
- it can be made operational by fiddling with "remote-gsyncd" tunable
- with default setting, an unhelpful, actually misleading error message is
  produced
- the UI gave no hint to the changes in the ssh setup

http://review.gluster.org/4392 tried to fix these; what it accomplished was
unrestricted support to the bad practice (by making the default old setup
operational).

From this on:
- we disable the old method by reserving the "remote-gsyncd" tunable
- if the old method is attempted, give a hint what to do

Change-Id: Icade94725d8d8d2d4c89cab992d4226351637b86
BUG: 895656
Signed-off-by: Csaba Henk 
Reviewed-on: http://review.gluster.org/4602
Reviewed-by: Venky Shankar 
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati