DPM Flushing Old Requests utility

Introduction

This page describes how to flush old requests (put, get, copy and bring online requests) of the DPM DB. Tables affected are dpm_put_filereq, dpm_get_filereq, dpm_req and dpm_copy_filereq. For the moment, the tool works only for MySQL DB. if you need it for Oracle, please send me a mail. This tool must be used as long as the flushing mechanism is not integrated in the DPM server.

Outline of the tool

The tool consists of a command line dpm-flush-req which takes the following input arguments:

• dpm_db_name : the DPM DB name (yaim uses by default dpm_db). However there is no default value
• dpm_db_host : the DPM MySQL DB host name (need to be put even if you run the command locally, i.e. if localhost is passed as dpm_db_host, the db connection will fail
• dpm_db_pwd : password of the DPM DB
• dpm_db_user : login od the DPM DB(yaim by default uses dpmmgr)
• max_request_lifetime : maximum time to keep a request in the tables. Time to be given in seconds. If this argument is omitted, the default value is 2592000

Installation

• Download and extract the tar file. Type make and if needed edit the makefile to match your environment.
• The executable and the log files will be located in the output directory.
• you will need mysql-devel : yum install mysql-devel

Example of usage

To delete old requests which have been performed two months (5270400 sec) before, type:

./dpm-flush-oldreq --dpm_db_name dpm_db --dpm_db_pwd  --dpm_db_host lxn1177.cernc.h --dpm_db_user dpm_mgr --max_request_lifetime 5270400

Then look at the log file produced dpm-flush-oldreq.log to see if the execution was successful.

Remark

if the number of requests to be flushed is very big around millions of row, it might be a good idea to start this script before migrating to a new DPM version so that it doesn't impact the performance of the DPM. it takes roughly one hour to delete around a few millions of old requests. Of course the execution time will depend on the DPM load.

Any problems or questions?

• if you get the following error in the log file: the total number of locks exceeds the lock table size, then you need to increase the innodb_buffer_size as follows:
  • edit your /etc/my.cnf (MySQL configurable parameters)
  • add in [mysqld] section : innodb_buffer_pool_size=256M (provided that this value does not exceed 80% of the physical memory of the machine).
  • restart mysql (service mysql/mysqld restart resp for SL3/SL4)

send me a mail

-- LanaAbadie - 15 Oct 2007