[Gluster-users] disperse volume file to subvolume mapping
Xavier Hernandez
xhernandez at datalab.es
Thu Apr 21 12:34:26 UTC 2016
Can you try a 'gluster volume rebalance v0 start force' ?
On 21/04/16 14:23, Serkan Çoban wrote:
>> Has the rebalance operation finished successfully ? has it skipped any files ?
> Yes according to gluster v rebalance status it is completed without any errors.
> rebalance status report is like:
> Node Rebalanced files size Scanned
> failures skipped
> 1.1.1.185 158 29GB 1720
> 0 314
> 1.1.1.205 93 46.5GB 761
> 0 95
> 1.1.1.225 74 37GB 779
> 0 94
>
>
> All other hosts has 0 values.
>
> I double check that files with '---------T' attributes are there,
> maybe some of them deleted but I still see them in bricks...
> I am also concerned why part files not distributed to all 60 nodes?
> Rebalance should do that?
>
> On Thu, Apr 21, 2016 at 1:55 PM, Xavier Hernandez <xhernandez at datalab.es> wrote:
>> Hi Serkan,
>>
>> On 21/04/16 12:39, Serkan Çoban wrote:
>>>
>>> I started a gluster v rebalance v0 start command hoping that it will
>>> equally redistribute files across 60 nodes but it did not do that...
>>> why it did not redistribute files? any thoughts?
>>
>>
>> Has the rebalance operation finished successfully ? has it skipped any files
>> ?
>>
>> After a successful rebalance all files with attributes '---------T' should
>> have disappeared.
>>
>>
>>>
>>> On Thu, Apr 21, 2016 at 11:24 AM, Xavier Hernandez
>>> <xhernandez at datalab.es> wrote:
>>>>
>>>> Hi Serkan,
>>>>
>>>> On 21/04/16 10:07, Serkan Çoban wrote:
>>>>>>
>>>>>>
>>>>>> I think the problem is in the temporary name that distcp gives to the
>>>>>> file while it's being copied before renaming it to the real name. Do
>>>>>> you
>>>>>> know what is the structure of this name ?
>>>>>
>>>>>
>>>>> Distcp temporary file name format is:
>>>>> ".distcp.tmp.attempt_1460381790773_0248_m_000001_0" and the same
>>>>> temporary file name used by one map process. For example I see in the
>>>>> logs that one map copies files part-m-00031,part-m-00047,part-m-00063
>>>>> sequentially and they all use same temporary file name above. So no
>>>>> original file name appears in temporary file name.
>>>>
>>>>
>>>>
>>>> This explains the problem. With the default options, DHT sends all files
>>>> to
>>>> the subvolume that should store a file named 'distcp.tmp'.
>>>>
>>>> With this temporary name format, little can be done.
>>>>
>>>>>
>>>>> I will check if we can modify distcp behaviour, or we have to write
>>>>> our mapreduce procedures instead of using distcp.
>>>>>
>>>>>> 2. define the option 'extra-hash-regex' to an expression that matches
>>>>>> your temporary file names and returns the same name that will finally
>>>>>> have.
>>>>>> Depending on the differences between original and temporary file names,
>>>>>> this
>>>>>> option could be useless.
>>>>>> 3. set the option 'rsync-hash-regex' to 'none'. This will prevent the
>>>>>> name conversion, so the files will be evenly distributed. However this
>>>>>> will
>>>>>> cause a lot of files placed in incorrect subvolumes, creating a lot of
>>>>>> link
>>>>>> files until a rebalance is executed.
>>>>>
>>>>>
>>>>>
>>>>> How can I set these options?
>>>>
>>>>
>>>>
>>>> You can set gluster options using:
>>>>
>>>> gluster volume set <volname> <option> <value>
>>>>
>>>> for example:
>>>>
>>>> gluster volume set v0 rsync-hash-regex none
>>>>
>>>> Xavi
>>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Apr 21, 2016 at 10:00 AM, Xavier Hernandez
>>>>> <xhernandez at datalab.es> wrote:
>>>>>>
>>>>>>
>>>>>> Hi Serkan,
>>>>>>
>>>>>> I think the problem is in the temporary name that distcp gives to the
>>>>>> file
>>>>>> while it's being copied before renaming it to the real name. Do you
>>>>>> know
>>>>>> what is the structure of this name ?
>>>>>>
>>>>>> DHT selects the subvolume (in this case the ec set) on which the file
>>>>>> will
>>>>>> be stored based on the name of the file. This has a problem when a file
>>>>>> is
>>>>>> being renamed, because this could change the subvolume where the file
>>>>>> should
>>>>>> be found.
>>>>>>
>>>>>> DHT has a feature to avoid incorrect file placements when executing
>>>>>> renames
>>>>>> for the rsync case. What it does is to check if the file matches the
>>>>>> following regular expression:
>>>>>>
>>>>>> ^\.(.+)\.[^.]+$
>>>>>>
>>>>>> If a match is found, it only considers the part between parenthesis to
>>>>>> calculate the destination subvolume.
>>>>>>
>>>>>> This is useful for rsync because temporary file names are constructed
>>>>>> in
>>>>>> the
>>>>>> following way: suppose the original filename is 'test'. The temporary
>>>>>> filename while rsync is being executed is made by prepending a dot and
>>>>>> appending '.<random chars>': .test.712hd
>>>>>>
>>>>>> As you can see, the original name and the part of the name between
>>>>>> parenthesis that matches the regular expression are the same. This
>>>>>> causes
>>>>>> that, after renaming the temporary file to its original filename, both
>>>>>> files
>>>>>> will be considered to belong to the same subvolume by DHT.
>>>>>>
>>>>>> In your case it's very probable that distcp uses a temporary name like
>>>>>> '.part.<number>'. In this case the portion of the name used to select
>>>>>> the
>>>>>> subvolume is always 'part'. This would explain why all files go to the
>>>>>> same
>>>>>> subvolume. Once the file is renamed to another name, DHT realizes that
>>>>>> it
>>>>>> should go to another subvolume. At this point it creates a link file
>>>>>> (those
>>>>>> files with access rights = '---------T') in the correct subvolume but
>>>>>> it
>>>>>> doesn't move it. As you can see, this kind of files are better
>>>>>> balanced.
>>>>>>
>>>>>> To solve this problem you have three options:
>>>>>>
>>>>>> 1. change the temporary filename used by distcp to correctly match the
>>>>>> regular expression. I'm not sure if this can be configured, but if this
>>>>>> is
>>>>>> possible, this is the best option.
>>>>>>
>>>>>> 2. define the option 'extra-hash-regex' to an expression that matches
>>>>>> your
>>>>>> temporary file names and returns the same name that will finally have.
>>>>>> Depending on the differences between original and temporary file names,
>>>>>> this
>>>>>> option could be useless.
>>>>>>
>>>>>> 3. set the option 'rsync-hash-regex' to 'none'. This will prevent the
>>>>>> name
>>>>>> conversion, so the files will be evenly distributed. However this will
>>>>>> cause
>>>>>> a lot of files placed in incorrect subvolumes, creating a lot of link
>>>>>> files
>>>>>> until a rebalance is executed.
>>>>>>
>>>>>> Xavi
>>>>>>
>>>>>>
>>>>>> On 20/04/16 14:13, Serkan Çoban wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Here is the steps that I do in detail and relevant output from bricks:
>>>>>>>
>>>>>>> I am using below command for volume creation:
>>>>>>> gluster volume create v0 disperse 20 redundancy 4 \
>>>>>>> 1.1.1.{185..204}:/bricks/02 \
>>>>>>> 1.1.1.{205..224}:/bricks/02 \
>>>>>>> 1.1.1.{225..244}:/bricks/02 \
>>>>>>> 1.1.1.{185..204}:/bricks/03 \
>>>>>>> 1.1.1.{205..224}:/bricks/03 \
>>>>>>> 1.1.1.{225..244}:/bricks/03 \
>>>>>>> 1.1.1.{185..204}:/bricks/04 \
>>>>>>> 1.1.1.{205..224}:/bricks/04 \
>>>>>>> 1.1.1.{225..244}:/bricks/04 \
>>>>>>> 1.1.1.{185..204}:/bricks/05 \
>>>>>>> 1.1.1.{205..224}:/bricks/05 \
>>>>>>> 1.1.1.{225..244}:/bricks/05 \
>>>>>>> 1.1.1.{185..204}:/bricks/06 \
>>>>>>> 1.1.1.{205..224}:/bricks/06 \
>>>>>>> 1.1.1.{225..244}:/bricks/06 \
>>>>>>> 1.1.1.{185..204}:/bricks/07 \
>>>>>>> 1.1.1.{205..224}:/bricks/07 \
>>>>>>> 1.1.1.{225..244}:/bricks/07 \
>>>>>>> 1.1.1.{185..204}:/bricks/08 \
>>>>>>> 1.1.1.{205..224}:/bricks/08 \
>>>>>>> 1.1.1.{225..244}:/bricks/08 \
>>>>>>> 1.1.1.{185..204}:/bricks/09 \
>>>>>>> 1.1.1.{205..224}:/bricks/09 \
>>>>>>> 1.1.1.{225..244}:/bricks/09 \
>>>>>>> 1.1.1.{185..204}:/bricks/10 \
>>>>>>> 1.1.1.{205..224}:/bricks/10 \
>>>>>>> 1.1.1.{225..244}:/bricks/10 \
>>>>>>> 1.1.1.{185..204}:/bricks/11 \
>>>>>>> 1.1.1.{205..224}:/bricks/11 \
>>>>>>> 1.1.1.{225..244}:/bricks/11 \
>>>>>>> 1.1.1.{185..204}:/bricks/12 \
>>>>>>> 1.1.1.{205..224}:/bricks/12 \
>>>>>>> 1.1.1.{225..244}:/bricks/12 \
>>>>>>> 1.1.1.{185..204}:/bricks/13 \
>>>>>>> 1.1.1.{205..224}:/bricks/13 \
>>>>>>> 1.1.1.{225..244}:/bricks/13 \
>>>>>>> 1.1.1.{185..204}:/bricks/14 \
>>>>>>> 1.1.1.{205..224}:/bricks/14 \
>>>>>>> 1.1.1.{225..244}:/bricks/14 \
>>>>>>> 1.1.1.{185..204}:/bricks/15 \
>>>>>>> 1.1.1.{205..224}:/bricks/15 \
>>>>>>> 1.1.1.{225..244}:/bricks/15 \
>>>>>>> 1.1.1.{185..204}:/bricks/16 \
>>>>>>> 1.1.1.{205..224}:/bricks/16 \
>>>>>>> 1.1.1.{225..244}:/bricks/16 \
>>>>>>> 1.1.1.{185..204}:/bricks/17 \
>>>>>>> 1.1.1.{205..224}:/bricks/17 \
>>>>>>> 1.1.1.{225..244}:/bricks/17 \
>>>>>>> 1.1.1.{185..204}:/bricks/18 \
>>>>>>> 1.1.1.{205..224}:/bricks/18 \
>>>>>>> 1.1.1.{225..244}:/bricks/18 \
>>>>>>> 1.1.1.{185..204}:/bricks/19 \
>>>>>>> 1.1.1.{205..224}:/bricks/19 \
>>>>>>> 1.1.1.{225..244}:/bricks/19 \
>>>>>>> 1.1.1.{185..204}:/bricks/20 \
>>>>>>> 1.1.1.{205..224}:/bricks/20 \
>>>>>>> 1.1.1.{225..244}:/bricks/20 \
>>>>>>> 1.1.1.{185..204}:/bricks/21 \
>>>>>>> 1.1.1.{205..224}:/bricks/21 \
>>>>>>> 1.1.1.{225..244}:/bricks/21 \
>>>>>>> 1.1.1.{185..204}:/bricks/22 \
>>>>>>> 1.1.1.{205..224}:/bricks/22 \
>>>>>>> 1.1.1.{225..244}:/bricks/22 \
>>>>>>> 1.1.1.{185..204}:/bricks/23 \
>>>>>>> 1.1.1.{205..224}:/bricks/23 \
>>>>>>> 1.1.1.{225..244}:/bricks/23 \
>>>>>>> 1.1.1.{185..204}:/bricks/24 \
>>>>>>> 1.1.1.{205..224}:/bricks/24 \
>>>>>>> 1.1.1.{225..244}:/bricks/24 \
>>>>>>> 1.1.1.{185..204}:/bricks/25 \
>>>>>>> 1.1.1.{205..224}:/bricks/25 \
>>>>>>> 1.1.1.{225..244}:/bricks/25 \
>>>>>>> 1.1.1.{185..204}:/bricks/26 \
>>>>>>> 1.1.1.{205..224}:/bricks/26 \
>>>>>>> 1.1.1.{225..244}:/bricks/26 \
>>>>>>> 1.1.1.{185..204}:/bricks/27 \
>>>>>>> 1.1.1.{205..224}:/bricks/27 \
>>>>>>> 1.1.1.{225..244}:/bricks/27 force
>>>>>>>
>>>>>>> then I mount volume on 50 clients:
>>>>>>> mount -t glusterfs 1.1.1.185:/v0 /mnt/gluster
>>>>>>>
>>>>>>> then I make a directory from one of the clients and chmod it.
>>>>>>> mkdir /mnt/gluster/s1 && chmod 777 /mnt/gluster/s1
>>>>>>>
>>>>>>> then I start distcp on clients, there are 1059X8.8GB files in one
>>>>>>> folder
>>>>>>> and
>>>>>>> they will be copied to /mnt/gluster/s1 with 100 parallel which means 2
>>>>>>> copy jobs per client at same time.
>>>>>>> hadoop distcp -m 100 http://nn1:8020/path/to/teragen-10tb
>>>>>>> file:///mnt/gluster/s1
>>>>>>>
>>>>>>> After job finished here is the status of s1 directory from bricks:
>>>>>>> s1 directory is present in all 1560 brick.
>>>>>>> s1/teragen-10tb folder is present in all 1560 brick.
>>>>>>>
>>>>>>> full listing of files in bricks:
>>>>>>> https://www.dropbox.com/s/rbgdxmrtwz8oya8/teragen_list.zip?dl=0
>>>>>>>
>>>>>>> You can ignore the .crc files in the brick output above, they are
>>>>>>> checksum files...
>>>>>>>
>>>>>>> As you can see part-m-xxxx files written only some bricks in nodes
>>>>>>> 0205..0224
>>>>>>> All bricks have some files but they have zero size.
>>>>>>>
>>>>>>> I increase file descriptors to 65k so it is not the issue...
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Apr 20, 2016 at 9:34 AM, Xavier Hernandez
>>>>>>> <xhernandez at datalab.es>
>>>>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Hi Serkan,
>>>>>>>>
>>>>>>>> On 19/04/16 15:16, Serkan Çoban wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> I assume that gluster is used to store the intermediate files
>>>>>>>>>>>> before
>>>>>>>>>>>> the reduce phase
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Nope, gluster is the destination for distcp command. hadoop distcp
>>>>>>>>> -m
>>>>>>>>> 50 http://nn1:8020/path/to/folder file:///mnt/gluster
>>>>>>>>> This run maps on datanodes which have /mnt/gluster mounted on all of
>>>>>>>>> them.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> I don't know hadoop, so I'm of little help here. However it seems
>>>>>>>> that
>>>>>>>> -m
>>>>>>>> 50
>>>>>>>> means to execute 50 copies in parallel. This means that even if the
>>>>>>>> distribution worked fine, at most 50 (much probably less) of the 78
>>>>>>>> ec
>>>>>>>> sets
>>>>>>>> would be used in parallel.
>>>>>>>>
>>>>>>>>>
>>>>>>>>>>>> This means that this is caused by some peculiarity of the
>>>>>>>>>>>> mapreduce.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Yes but how a client write 500 files to gluster mount and those file
>>>>>>>>> just written only to subset of subvolumes? I cannot use gluster as a
>>>>>>>>> backup cluster if I cannot write with distcp.
>>>>>>>>>
>>>>>>>>
>>>>>>>> All 500 files were created only on one of the 78 ec sets and the
>>>>>>>> remaining
>>>>>>>> 77 got empty ?
>>>>>>>>
>>>>>>>>>>>> You should look which files are created in each brick and how
>>>>>>>>>>>> many
>>>>>>>>>>>> while the process is running.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Files only created on nodes 185..204 or 205..224 or 225..244. Only
>>>>>>>>> on
>>>>>>>>> 20 nodes in each test.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> How many files there were in each brick ?
>>>>>>>>
>>>>>>>> Not sure if this can be related, but standard linux distributions
>>>>>>>> have
>>>>>>>> a
>>>>>>>> default limit of 1024 open file descriptors. Having a so big volume
>>>>>>>> and
>>>>>>>> doing a massive copy, maybe this limit is affecting something ?
>>>>>>>>
>>>>>>>> Are there any error or warning messages in the mount or bricks logs ?
>>>>>>>>
>>>>>>>>
>>>>>>>> Xavi
>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Tue, Apr 19, 2016 at 1:05 PM, Xavier Hernandez
>>>>>>>>> <xhernandez at datalab.es>
>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Hi Serkan,
>>>>>>>>>>
>>>>>>>>>> moved to gluster-users since this doesn't belong to devel list.
>>>>>>>>>>
>>>>>>>>>> On 19/04/16 11:24, Serkan Çoban wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> I am copying 10.000 files to gluster volume using mapreduce on
>>>>>>>>>>> clients. Each map process took one file at a time and copy it to
>>>>>>>>>>> gluster volume.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I assume that gluster is used to store the intermediate files
>>>>>>>>>> before
>>>>>>>>>> the
>>>>>>>>>> reduce phase.
>>>>>>>>>>
>>>>>>>>>>> My disperse volume consist of 78 subvolumes of 16+4 disk each. So
>>>>>>>>>>> If
>>>>>>>>>>> I
>>>>>>>>>>> copy >78 files parallel I expect each file goes to different
>>>>>>>>>>> subvolume
>>>>>>>>>>> right?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> If you only copy 78 files, most probably you will get some
>>>>>>>>>> subvolume
>>>>>>>>>> empty
>>>>>>>>>> and some other with more than one or two files. It's not an exact
>>>>>>>>>> distribution, it's a statistially balanced distribution: over time
>>>>>>>>>> and
>>>>>>>>>> with
>>>>>>>>>> enough files, each brick will contain an amount of files in the
>>>>>>>>>> same
>>>>>>>>>> order
>>>>>>>>>> of magnitude, but they won't have the *same* number of files.
>>>>>>>>>>
>>>>>>>>>>> In my tests during tests with fio I can see every file goes to
>>>>>>>>>>> different subvolume, but when I start mapreduce process from
>>>>>>>>>>> clients
>>>>>>>>>>> only 78/3=26 subvolumes used for writing files.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> This means that this is caused by some peculiarity of the
>>>>>>>>>> mapreduce.
>>>>>>>>>>
>>>>>>>>>>> I see that clearly from network traffic. Mapreduce on client side
>>>>>>>>>>> can
>>>>>>>>>>> be run multi thread. I tested with 1-5-10 threads on each client
>>>>>>>>>>> but
>>>>>>>>>>> every time only 26 subvolumes used.
>>>>>>>>>>> How can I debug the issue further?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> You should look which files are created in each brick and how many
>>>>>>>>>> while
>>>>>>>>>> the
>>>>>>>>>> process is running.
>>>>>>>>>>
>>>>>>>>>> Xavi
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Tue, Apr 19, 2016 at 11:22 AM, Xavier Hernandez
>>>>>>>>>>> <xhernandez at datalab.es> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Hi Serkan,
>>>>>>>>>>>>
>>>>>>>>>>>> On 19/04/16 09:18, Serkan Çoban wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Hi, I just reinstalled fresh 3.7.11 and I am seeing the same
>>>>>>>>>>>>> behavior.
>>>>>>>>>>>>> 50 clients copying part-0-xxxx named files using mapreduce to
>>>>>>>>>>>>> gluster
>>>>>>>>>>>>> using one thread per server and they are using only 20 servers
>>>>>>>>>>>>> out
>>>>>>>>>>>>> of
>>>>>>>>>>>>> 60. On the other hand fio tests use all the servers. Anything I
>>>>>>>>>>>>> can
>>>>>>>>>>>>> do
>>>>>>>>>>>>> to solve the issue?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Distribution of files to ec sets is done by dht. In theory if you
>>>>>>>>>>>> create
>>>>>>>>>>>> many files each ec set will receive the same amount of files.
>>>>>>>>>>>> However
>>>>>>>>>>>> when
>>>>>>>>>>>> the number of files is small enough, statistics can fail.
>>>>>>>>>>>>
>>>>>>>>>>>> Not sure what you are doing exactly, but a mapreduce procedure
>>>>>>>>>>>> generally
>>>>>>>>>>>> only creates a single output. In that case it makes sense that
>>>>>>>>>>>> only
>>>>>>>>>>>> one
>>>>>>>>>>>> ec
>>>>>>>>>>>> set is used. If you want to use all ec sets for a single file,
>>>>>>>>>>>> you
>>>>>>>>>>>> should
>>>>>>>>>>>> enable sharding (I haven't tested that) or split the result in
>>>>>>>>>>>> multiple
>>>>>>>>>>>> files.
>>>>>>>>>>>>
>>>>>>>>>>>> Xavi
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>> Serkan
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> ---------- Forwarded message ----------
>>>>>>>>>>>>> From: Serkan Çoban <cobanserkan at gmail.com>
>>>>>>>>>>>>> Date: Mon, Apr 18, 2016 at 2:39 PM
>>>>>>>>>>>>> Subject: disperse volume file to subvolume mapping
>>>>>>>>>>>>> To: Gluster Users <gluster-users at gluster.org>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Hi, I have a problem where clients are using only 1/3 of nodes
>>>>>>>>>>>>> in
>>>>>>>>>>>>> disperse volume for writing.
>>>>>>>>>>>>> I am testing from 50 clients using 1 to 10 threads with file
>>>>>>>>>>>>> names
>>>>>>>>>>>>> part-0-xxxx.
>>>>>>>>>>>>> What I see is clients only use 20 nodes for writing. How is the
>>>>>>>>>>>>> file
>>>>>>>>>>>>> name to sub volume hashing is done? Is this related to file
>>>>>>>>>>>>> names
>>>>>>>>>>>>> are
>>>>>>>>>>>>> similar?
>>>>>>>>>>>>>
>>>>>>>>>>>>> My cluster is 3.7.10 with 60 nodes each has 26 disks. Disperse
>>>>>>>>>>>>> volume
>>>>>>>>>>>>> is 78 x (16+4). Only 26 out of 78 sub volumes used during
>>>>>>>>>>>>> writes..
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>
>>
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