[Gluster-devel] Files not available in all clients immediately

[Anand Avati]

Do you have logs from the client when you see this behaviour?

avati

2008/3/19, Claudio Cuqui <claudio at c3systems.com.br>:
>
> Hi there !
>
> We are using gluster on an environment with multiple webservers and load
> balancer, where we have only one server and multiple clients (6).
> All servers are running Fedora Core 6 X86_64 with kernel
> 2.6.22.14-72.fc6 (with exactly same packages installed in all server).
> The gluster version used is 1.3.8pre2 + 2.7.2glfs8 (both compiled
> locally). The underlying FS is reiserfs mounted with the follow options
> rw,noatime,nodiratime,notail. This filesystem has almost 4 thousand
> files from 2k - 10Mb in size. We are using gluster to export this
> filesystem for all other webservers. Below the config file used by
> gluster server:
>
> ### Export volume "brick" with the contents of "/home/export" directory.
> volume attachments-nl
>   type storage/posix                   # POSIX FS translator
>   option directory /C3Systems/data/domains/webmail.pop.com.br/attachments
> end-volume
>
> volume attachments
>   type features/posix-locks
>   subvolumes attachments-nl
>   option mandatory on
> end-volume
>
>
> ### Add network serving capability to above brick.
> volume server
>   type protocol/server
>   option transport-type tcp/server     # For TCP/IP transport
>   option client-volume-filename
> /C3Systems/gluster/bin/etc/glusterfs/glusterfs-client.vol
>   subvolumes attachments-nl attachments
>   option auth.ip.attachments-nl.allow * # Allow access to
> "attachments-nl" volume
>   option auth.ip.attachments.allow * # Allow access to "attachments"
> volume
> end-volume
>
> The problem happen when the LB sent the post (the uploaded file) to one
> webserver and than the next post goes to other webserver  that try to
> access the same file. When this happen, the other client got these
> messages:
>
> PHP Warning:
>
> fopen(/C3Systems/data/domains/c3systems.com.br/attachments/27gBgFQSIiOLDEo7AvxlpsFkqZw9jdnZ):
> failed to open stream: File Not Found.
> PHP Warning:
>
> unlink(/C3Systems/data/domains/c3systems.com.br/attachments/5Dech7jNxjORZ2cZ9IAbR7kmgmgn2vTE):
> File Not Found.
>
> LB is using RoundRobin to distribute the load between servers.
>
> Below, you can find the gluster configuration file used by all clients:
>
> ### file: client-volume.spec.sample
>
> ##############################################
> ###  GlusterFS Client Volume Specification  ##
> ##############################################
>
> #### CONFIG FILE RULES:
> ### "#" is comment character.
> ### - Config file is case sensitive
> ### - Options within a volume block can be in any order.
> ### - Spaces or tabs are used as delimitter within a line.
> ### - Each option should end within a line.
> ### - Missing or commented fields will assume default values.
> ### - Blank/commented lines are allowed.
> ### - Sub-volumes should already be defined above before referring.
>
> ### Add client feature and attach to remote subvolume
> volume client
>   type protocol/client
>   option transport-type tcp/client     # for TCP/IP transport
> # option ib-verbs-work-request-send-size  1048576
> # option ib-verbs-work-request-send-count 16
> # option ib-verbs-work-request-recv-size  1048576
> # option ib-verbs-work-request-recv-count 16
> # option transport-type ib-sdp/client  # for Infiniband transport
> # option transport-type ib-verbs/client # for ib-verbs transport
>   option remote-host 1.2.3.4      # IP address of the remote brick
> # option remote-port 6996              # default server port is 6996
>
> # option transport-timeout 30          # seconds to wait for a reply
>                                        # from server for each request
>   option remote-subvolume attachments  # name of the remote volume
> end-volume
>
> ### Add readahead feature
> volume readahead
>   type performance/read-ahead
>   option page-size 1MB     # unit in bytes
>   option page-count 2       # cache per file  = (page-count x page-size)
>   subvolumes client
> end-volume
>
> ### Add IO-Cache feature
> volume iocache
>   type performance/io-cache
>   option page-size 256KB
>   option page-count 2
>   subvolumes readahead
> end-volume
>
> ### Add writeback feature
> #volume writeback
> #  type performance/write-behind
> #  option aggregate-size 1MB
> #  option flush-behind off
> #  subvolumes iocache
> #end-volume
>
> When I do the test manually, everything goes fine. What I think is
> happening is that gluster isn´t having enough time to sync all clients
> before clients trying to access the files (those servers are very busy
> ones.....they receive millions of requests per day).
>
> Is this configuration appropriate for this situation ? a bug ? a feature
> ;-) ? Is there any option like the sync used in NFS that I can use in
> order guarantee that when the file is write down, all the clients already
> have it ?
>
> TIA,
>
> Claudio Cuqui
>
>
>
>
>
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>



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