Arc 0 8 migration notes

Migration notes:

New dependencies: BDII

The new ARC 0.8 Release have moved to using BDIIv4+System OpenLDAP instead of Globus MDS and the OpenLDAP provided by Globus. This affects you in the way that you need to install BDII from the gLite project.

BDIIv4 consists of a set of perl scripts that take care of populating the LDAP database with the information that will be available in the GRIS. This is done by giving it a set of providers that will mine data from the system.

BDIIv4 runs two LDAP servers consecutively and while one LDAP server is populated, the other one is serving requests. Then when the new data has been entered, BDII uses its port-forward service to let the LDAP server with the new data service requests while the old one is repopulated with data.

BDII is installed in /opt/bdii and /etc/init.d/{bdii,bdii-update,bdii-fwd,bdii-proxy}

One note on BDII. The version that resides in the nordugrid repositories is a patched BDII that allows you to turn on/off the bdii self-monitoring service. If you want to turn it off for some reason, you must either use BDII from the nordgrid repository or download the patch that add this functionality from: http://svn.nordugrid.org/repos/workarea/gris-replacement/bdii-patches/bdii-update.patch

If you are using a system where /bin/sh IS NOT equal to /bin/bash, then you will need: http://svn.nordugrid.org/repos/workarea/gris-replacement/bdii-patches/bdii.patch This is true for example on Ubuntu where /bin/sh points to the more sh-strict Dash shell.

Things regarding Globus:

There are only two things from Globus that have made the transition to ARC 0.8.

• grid-info-soft-register

The information registration script has been modified and incorporated into ARC.

• LDAP OID

The Globus MDS LDAP Schema that was used earlier has been updated to be a proper LDAP Schema and has thus been moved into the Nordugrid LDAP Namespace.

Non-portable optimizations

In order to continue our widespread support for different platforms, some non-portable optimizations had to be removed from code that we have incorporated into ARC. If you find performance issues with these components (Very unlikely), You might want to try modifying them the following way:

• grid-info-soft-register

You can modify the script infosys/grid-info-soft-register and set:

 # set default network timeout to 30 seconds
 DEFAULT_NETWORK_TIMEOUT="-o nettimeout=30"

If you encounter many stale connections.

This requires your OpenLDAP to be newer than 2.3.x (the version in RHEL5 is know to not work with this setting.)

• BDII

If you want to speed up your information system you can manipulate logging by doing one of the two options below depending on what version of BDB you have.

a) If you are using BDB < 4.3 Set this flag in DB_CONFIG:

 set_flags DB_TXN_NOT_DURABLE

b) If you are using BDB >= 4.3 (True on CentOS5) you can set these two parameters in /opt/bdii/DB_CONFIG with a suitable size for the logging cache

 set_flags DB_LOG_INMEMORY
 set_lg_bsize            20485760

Changes to arc.conf:

A new feature has been added to arc.conf, that is the possibility to publish data in both the Nordugrid Mds schema as well as the gLite Glue 1.2 schema. These can be turned on by setting these these variables in arc.conf:

 infosys_nordugrid=enable
 infosys_glue12=enable 

The default will show the same behaviour as before, i.e. nordugrid=enable and glue=disable. if glue is turned on, it will be added under "mds-vo-name=glue12,o=grid"

BDII can be fully configured from arc.conf, this however should not be necessary. More information can be found in the documentation for arc.conf.