glusterfs.git/rpc/rpc-lib/src, branch v3.5.0qa3

features/quota: Improvements to quota

2013-11-26T18:24:02+00:00

* Two stages of quota enforcement is done:

  Soft and hard quota Upon reaching soft quota limit on the directory
  it logs/alerts in the quota daemon log (ie DEFAULT_LOG_DIR/quotad.log)
  and no more writes allowed after hard
  quota limit. After reaching the soft-limit the daemon alerts the
  user/admin repeatively for every 'alert-time', which is
  configurable.

* Quota enforcer is moved to server-side.

  It  takes care of enforcing quota. Since enforcer doesn't have the
  cluster view, it relies on another service called
  quota-aggregator. Aggregator, on query can return the size of a
  directory based on the cluster view.

  Enforcer is always loaded in the server graph and is by passed if
  the feature is not enabled.

  Options specific to enforcer:

  server-quota - Specifies whether the feature is on/off. It is used
  to by pass the quota if turned off.

  deem-statfs - If set to on, it takes quota limits into consideration
  while estimating fs size. (df command). The algorithm followed is,
  i.   Adjust statvfs based on limit configured on root.
  ii.  If limit is set on the inode passed, use size/limits on that inode to
       populate statvfs. Otherwise, use size/limits configured on root.
  iii. Upon statvfs, update the ctx->size on the inode.
  iv.  Don't let DHT aggregate, instead take the maximum of the usages from the
       subvols of the DHT, since each of it contains the complete information.

  Enforcer also makes use of gfid-to-path conversion functionality to
  work correctly when a client like nfs predominently relies on
  nameless lookups.

* Quota Aggregator acts as a thin client to provide cluster view

  Its a lightweight *gluster client* process with no mount point,
  started upon enabling quota or restarting the volume. This is a
  single process run on each brick, which can answer queries on all
  volumes in the cluster. Its volfile stored in
  GLUSTERD_DEFAULT_WORKING_DIR/quotad/quotad.vol.

Credits:
Raghavendra Bhat        
Varun Shastry           
Shishir Gowda           
Kruthika Dhananjay      
Brian Foster            
Krishnan Parthasarathi  

Change-Id: Id1cb25b414951da34c665a55f77385d482e0f9de
BUG: 969461
Signed-off-by: Raghavendra G 
Reviewed-on: http://review.gluster.org/5952
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

gNFS: More clean up for Gluster NFS

2013-11-25T13:40:57+00:00

1) Fix the typo in NFS default ACL
   The typo was introduced as part of the Fix to BZ 1009210 i.e.
   http://review.gluster.org/5980. The user ACL xattr structure
   was passed to default ACL xattr.

2) Clean up NFS code to avoid unnecessary SEGV in
   rpcsvc_drc_reconfigure() which was not validating the
   svc->drc. Add a routine rpcsvc_drc_deinit() to handle
   the clean up of DRC specific data structures. For init(),
   use rpcsvc_drc_init().

3) nfs_init_state() was returning wrong value even if the
   registration with portmapper failed, causing the NFS
   server process to hang around. As a result it used to
   get SEGV during rpcsvc_drc_reconfigure().

4) Clean up memfactor usage across nfs.c nfs3.c.

Change-Id: I5cea26cb68dd8a822ec0ae104952f67fe63fa703
BUG: 1009210
Signed-off-by: Santosh Kumar Pradhan 
Reviewed-on: http://review.gluster.org/6329
Reviewed-by: Rajesh Joseph 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

gNFS: RFE for NFS connection behavior

2013-11-15T00:07:02+00:00

Implement reconfigure() for NFS xlator so that volume set/reset wont
restart the NFS server process. But few options can not be reconfigured
dynamically e.g. nfs.mem-factor, nfs.port etc which needs NFS to be
restarted.

Change-Id: Ic586fd55b7933c0a3175708d8c41ed0475d74a1c
BUG: 1027409
Signed-off-by: Santosh Kumar Pradhan 
Reviewed-on: http://review.gluster.org/6236
Tested-by: Gluster Build System 
Reviewed-by: Rajesh Joseph 
Reviewed-by: Anand Avati

bd_map: Remove bd_map xlator

2013-11-13T19:38:28+00:00

Remove bd_map xlator and CLI related changes.

Change-Id: If7086205df1907127c1a1fa4ba603f1c48421d09
BUG: 1028672
Signed-off-by: M. Mohan Kumar 
Reviewed-on: http://review.gluster.org/5747
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

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

rpcsvc: implement per-client RPC throttling

2013-10-28T07:33:19+00:00

Implement a limit on the total number of outstanding RPC requests
from a given cient. Once the limit is reached the client socket
is removed from POLL-IN event polling.

Change-Id: I8071b8c89b78d02e830e6af5a540308199d6bdcd
BUG: 1008301
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6114
Reviewed-by: Santosh Pradhan 
Reviewed-by: Rajesh Joseph 
Reviewed-by: Harshavardhana 
Reviewed-by: Vijay Bellur 
Tested-by: Gluster Build System

rpc: add remote peer's hostname to call_bail log msgs

2013-10-18T00:14:19+00:00

Change-Id: I982cf7619463983c04b401d70a76635991d072d2
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/6091
Reviewed-by: Niels de Vos 
Reviewed-by: Kaushal M 
Tested-by: Gluster Build System 
Reviewed-by: Harshavardhana

libglusterfs: Add monotonic clocking counter for timer thread

2013-10-15T07:14:57+00:00

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 
Reviewed-on: http://review.gluster.org/6070
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/afr: [Feature] Command implementation to get heal-count

2013-10-14T21:41:54+00:00

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  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 
Reviewed-on: http://review.gluster.org/6044
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/afr : Implementation of command "gluster volume heal vn statistics"

2013-10-14T21:41:44+00:00

"gluster volume heal volumename statistics" command gives the summary
of the afr crawl done based on the entries present in the xattrop
directory. Whenever afr crawls are attempted, the beginning time of
crawl, end time of crawl, no of files healed, heal-failed count and
number of files in split brain are shown along with the type of the
crawl. If crawl is already in progress then it will give the number
of files healed, heal failed count and number of files in split-brain
from the beginning of the crawl and instead of telling the end time of
the crawl, "CRAWL IN PROGRESS" message will be shown.

Output format:
command: "gluster volume heal volume-name statistics"
Output:
Gathering afr crawl statistics crawl statistics on volume volume-name
has been successful
------------------------------------------------

Crawl statistics for brick no 0
Hostname of brick 192.168.122.248

Starting time of crawl: Wed Jul 10 15:52:38 2013

Ending time of crawl: Wed Jul 10 15:52:38 2013

Type of crawl: INDEX
No. of entries healed: 0
No. of entries in split-brain: 0
No. of heal failed entries: 0

Starting time of crawl: Wed Jul 10 15:52:38 2013

Ending time of crawl: Wed Jul 10 15:52:38 2013

Type of crawl: INDEX
No. of entries healed: 0
No. of entries in split-brain: 0
No. of heal failed entries: 0

------------------------------------------------

Crawl statistics for brick no 1
Hostname of brick 192.168.122.1

Starting time of crawl: Wed Jul 10 15:52:42 2013

Ending time of crawl: Wed Jul 10 15:52:42 2013

Type of crawl: INDEX
No. of entries healed: 0
No. of entries in split-brain: 0
No. of heal failed entries: 0

Starting time of crawl: Wed Jul 10 15:52:42 2013

Ending time of crawl: Wed Jul 10 15:52:42 2013

Type of crawl: INDEX
No. of entries healed: 0
No. of entries in split-brain: 0
No. of heal failed entries: 0

--------------------------------------------------

Change-Id: I10bf9d10b005741db9973fb1352e0dd59ed99aa9
BUG: 949400
Signed-off-by: Venkatesh Somyajulu 
Reviewed-on: http://review.gluster.org/4790
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati