Configuration tips for EUMED WMS/LB

This section details some simple configuration tips which ought to be performed by site-managers administering a WMS/LB server(s) supporting the eumed VO: if the WMS server is dedicated to eumed, these steps are considered mandatory.

Configuration for RTM

The Real Time Monitor (RTM) (or go directly to the application) is a very effective way to visually show what is going on in the GRID: resources made available by sites, jobs being submitted and retrieved, and so on. Enabling your WMS/LB to be part of the game is just a matter of a few simple steps. All steps below need to be executed on your LB server only.

• As a pre-requisite, make sure your VO publishes somewhere on the web the configuration file of the topBDII, and make sure that your WMS reads it; for the eumed VO such configuration file is available at the URL http://www.eumedgrid.eu/conf/eumed-bdii.conf
• in the site-info.def add the following lines:

     GLITE_LB_RTM_ENABLED= "true"
     GLITE_LB_RTM_DN="/C=UK/O=eScience/OU=Imperial/L=Physics/CN=heppc24.hep.ph.ic.ac.uk/Email=janusz.martyniak@imperial.ac.uk" 
     

• after successful configuration of the LB service, please execute the following steps on the appropriate box where the Logging & Bookkeeping MySQL database is running:

     mysql -u root -p
     <enter your mysql pass - in YAIM site-info.def>
     GRANT SELECT ON lbserver20.events TO 'lcg2mon'@'tl00.hep.ph.ic.ac.uk' IDENTIFIED BY 'TnoomG' ;
     GRANT SELECT ON lbserver20.states TO 'lcg2mon'@'tl00.hep.ph.ic.ac.uk' IDENTIFIED BY 'TnoomG' ;
     GRANT SELECT ON lbserver20.short_fields TO 'lcg2mon'@'tl00.hep.ph.ic.ac.uk' IDENTIFIED BY 'TnoomG' ;
     FLUSH PRIVILEGES;
     

• check the grants issuing the command (still in the MySQL session):

     select * from tables_priv;
     

• make sure any firewalls are not blocking connections to your MySQL server from the IP address tl00.hep.ph.ic.ac.uk

As soon as you have completed the procedure, please inform Riccardo Bruno, sending him an email containing the hostname of the LB service and the output from the select * from tables_priv command above.

Check your configuration

It is possible to verify if RTM can retrieve data by executing the following LDAP query:

ldapsearch -LLL -x -H ldap://bdii.eumedgrid.eu:2170 -b mds-vo-name=local,o=grid '(&(objectClass=GlueService)(GlueForeignKey=GlueSiteUniqueID=<site-name>))'

This is the query that RTM does against the topBDIIs to retrieve site data.

Configuration for WMSmon

The WMSMON collector page is available at this link. It shows a lot of information about the WMS service, including its health status.

Detailed instructions as to how to install the WMSMON on the WMS and LB are available at this Twiki page. Note that you need to follow only the instructions at the paragraph WMSMON Sensors installation on WMS/LB/WMSLB nodes. Repeat the following steps on the WMS and the LB servers (if you have them on two separate hosts).

• install the yum repo file
• install the package
• edit file /opt/WMSMonitor/common/wmsmon_site-info.def: normally you would just need to change the following variables

  WMSMON_HOST = wmsmon.ct.infn.it

  this is the wms collector

  WMSMON_SEVER_CONTACT_EMAIL = ...

  yes, it's really SEVER, not SERVER; enter an email address users can contact in case of troubles

  SERVER_MYSQL_PASSWORD = ...

  this is the same as MYSQL_PASSWORD in your site-info.def

  LB_PARA_HOST = https://wmsmon.ct.infn.it:8443

  this is the name of the WMSmon collector instance

  SNMPPASSWD = 'an_snmp_passwd'

  this is the password used by the wmsmon collector to communicate with your servers

• cd /opt/WMSMonitor/sensors/etc
• ./WMSLB_wmsmon_configuration.py

Again, please repeat the above steps on the WMS and the LB.

In case of problems during the configuration of the WMS/LB, please contact the author of the wiki, or Riccardo Bruno to get help.

Configuration for statistics gathering

If you maintain a WMS, you are kindly asked to allow access to the Logging and Bookkeeping database, so that statistics about user submitted jobs may be gathered.

• login as root on the LB server and execute the following commands:

   mysql -u root -p
   <enter your mysql pass - in YAIM site-info.def>
   GRANT SELECT ON lbserver20.users TO 'lbreader'@'%' IDENTIFIED BY '3Um3D_LB_R3ad3r';
   GRANT SELECT ON lbserver20.events TO 'lbreader'@'%' IDENTIFIED BY '3Um3D_LB_R3ad3r';
   GRANT SELECT ON lbserver20.long_fields TO 'lbreader'@'%' IDENTIFIED BY '3Um3D_LB_R3ad3r';
   FLUSH PRIVILEGES;
   

The password for lbreader (namely the string after IDENTIFIED BY) can be different from the one suggested: if you change it, please remember to let Riccardo Bruno know it. You may also restrict the GRANT opening only to following hostnames instead of %: ui2-4.dir.garr.it (mandatory), areagrid.ct.infn.it (optional but recommended), jessica.trigrid.it (optional)

• check the grants, by issuing the command (still in the MySQL session):

•    show grants for lbreader;
     

• make sure any firewalls are not blocking connections to your MySQL server blocking the port 3306 (default).
• ensure any firewall is not blocking incoming connections on port 3306 (which is the default mysql server port or any alternative mysql port you defined) from the IP addresses (193.206.208.201,193.206.219.199 and 193.206.106.21)
• as soon as you have completed the procedure, please inform Riccardo Bruno, sending him an email containing: the hostname of the LB service, the password you assigned to user 'lbreader' and the output from the show grants command above.

-- FulvioGaleazzi - 2011-03-02</verbatim>