Gluster users - Apr 2017 - writing small 16Mb files many times a min from postgresql to Glusterfs client file system

Hi,

        We have a postgresdb that streams archive logs into a glusterfs 
mount point.  Their writing process shows continuous writes but not any 
flush or close system calls.   During this writing the virtual memory of 
the glusterfs process gradually increases that it eventually surpasses the 
amount of system memory.  And then other processes cannot start because 
shared memory cannot be allocated.

Each file 'chunk' written is 16Mb and writes are up to 100 a minuet.

The postgresql process is /opt/PostgresPlus/9.4AS/bin/pg_receivexlog

My work around is to stop the archive log writer pg_receivexlog and 
unmount the glusterfs file systems, which frees the virtual memory, mount 
the file system and start pg_receivexlog. 

We plan to replace our RedHat gluster setup with community Glusterfs, but 
I would like to know if gluster is suitable for this type of writing.

Or did we hit a bug?




Client
3.10.0-514.el7.x86_64 / RHEL 7.3
# rpm -qa|grep -i gluster
glusterfs-3.7.9-12.el7.x86_64
glusterfs-client-xlators-3.7.9-12.el7.x86_64
glusterfs-fuse-3.7.9-12.el7.x86_64
glusterfs-libs-3.7.9-12.el7.x86_64
Process: 
# ps -eaf |grep glusterfs
root     12593     1  0 Mar30 ?        00:13:27 /usr/sbin/glusterfs --acl 
--volfile-server=glustersrv1.int.local 
--volfile-server=glustersrv1.int.local --volfile-id=/db_backup_111 
/backup_111_2

Server
2.6.32-573.12.1.el6.x86_64  /  RHEL 6.8
# rpm -qa |grep -i gluster
glusterfs-3.6.0.29-1.el6rhs.x86_64
glusterfs-cli-3.6.0.29-1.el6rhs.x86_64
glusterfs-geo-replication-3.6.0.29-1.el6rhs.x86_64
glusterfs-libs-3.6.0.29-1.el6rhs.x86_64
glusterfs-fuse-3.6.0.29-1.el6rhs.x86_64
glusterfs-server-3.6.0.29-1.el6rhs.x86_64
gluster-nagios-addons-0.1.10-2.el6rhs.x86_64
vdsm-gluster-4.14.7.2-1.el6rhs.noarch
samba-glusterfs-3.6.23-35.el6_8.x86_64
glusterfs-api-3.6.0.29-1.el6rhs.x86_64
gluster-nagios-common-0.1.3-2.el6rhs.noarch
glusterfs-rdma-3.6.0.29-1.el6rhs.x86_64

Kind regards,
Sophie Loewenthal

Server Infrastructure
Smals.be
















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