skahler


What kind of disk performance does your GP see?

Posted by skahler on

During our regular maintenance widows I run a gpcheckperf to see where our disk speeds in the Greenplum cluster are coming in. This is a result from an C2100 with a single LSI 9260-8i  controller. There are two virtual disk composed of 6 disks each arranged in a RAID5. For the file system I’m using xfs with the mount options: logbufs=8, logbsize=256k, noatime, attr2, nobarrier and seeing these results.

/usr/local/greenplum-db/./bin/gpcheckperf -f /data/gpadmin/hosts.seg -d /data/gpdb_p1 -d /data/gpdb_p2 -r d -D

disk write min bandwidth (MB/s): 945.25 [sdw15]
disk write max bandwidth (MB/s): 1007.74 [sdw13]

disk read min bandwidth (MB/s): 1239.10 [sdw15]
disk read max bandwidth (MB/s): 1691.65 [sdw12]

Are these similar number to what you are getting in your clusters?

Adding plperlu Language to Greenplum on RHEL5

Posted by skahler on

In order to get plperlu added as a language on our Greenplum 4.0RHEL5 cluster I had to take a couple additional steps. My first unhappy message was

db=# CREATE LANGUAGE plperlu;
ERROR:  could not load library “/usr/local/greenplum-db-4.0.4.3/lib/postgresql/plperl.so”:
libperl.so: cannot open shared object file: No such file or directory
db=# CREATE LANGUAGE plperlu;ERROR:  could not load library “/usr/local/greenplum-db-4.0.4.3/lib/postgresql/plperl.so”:
libperl.so: cannot open shared object file: No such file or directory

So greenplum can’t find libperl.so

[gpadmin@mdw ~]$ locate libperl.so

/usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE/libperl.so

Looks like it’s on the system so I just need to make it available

[root@mdw ~]# echo “/usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE/” > /etc/ld.so.conf.d/perl.conf

[root@mdw ~]# ldconfig

Next I went out and did the same thing on all the nodes using gpssh. Then it’s back to the master and we try to create the language again

db=# CREATE LANGUAGE plperlu;

CREATE LANGUAGE

Time: 892.420 ms

I should note that I tried to install plperl on the SLES11 servers we had and ran into an issue because the version of perl on SLES11 is 5.10 and unfortunately the plperl.so within Greenplum’s distro is looking for 5.8. I didn’t look for a fix because I knew we were going to jump to Redhat in the near future and it would work there.

Alpine Miner First Look

Posted by skahler on

Downloaded the new Alpine Miner off of the the Greenplum Community site. Unfortunately for me there is only a Mac and Windows version so I had to fire up a VM to try it out.

Adding Documentation

Posted by skahler on

Doing the most exciting of all tasks, I’m adding documentation to the site.

Greenplum Command references at : GP COMMANDS

Greenplum Documentation at: DOCS

I find myself constantly sharing my latest GP Admin guide with other people so I figured this would be a great spot to drop the pdf documentation that you’ll find in the release packages. It would also be handy to keep a running log the various documentation attached with each release.

Additionally I’m using <command> -? constantly to get the help from the program I want to run. So I put these up on the site too in order to make it easier to get at those outputs.

More Info Soon

Posted by skahler on

Gearing up and planning to put this site into action. The goal to be a repository for Greenplum ideas and tips submitted and maintained by people using the system.