The location of the THL directory where THL files are stored can be changed, either by using a symbolic link or by changing the configuration to point to the new directory:
Changing the directory location using symbolic links can be used in an emergency if the space on a filesystem has been exhausted. See Section 6.18.1.1, “Relocating THL Storage using Symbolic Links”
Changing the directory location through reconfiguration can be used when a permanent change to the THL location is required. See Section 6.18.1.2, “Relocating THL Storage using Configuration Changes”.
In an emergency, the directory currently holding the THL information, can be moved using symbolic links to relocate the files to a location with more space.
Moving the THL location requires updating the location for a Replica by temporarily setting the Replica offline, updating the THL location, and re-enabling back into the cluster:
Shun the datasource and switch your node into the offline state using cctrl:
shell>cctrl -expert[LOGICAL:EXPERT] /alpha >datasource host1 shun[LOGICAL:EXPERT] /alpha >replicator host1 offline
Create a new directory, or attach a new filesystem and location on which the THL content will be located. You can use a directory on another filesystem or connect to a SAN, NFS or other filesystem where the new directory will be located. For example:
shell> mkdir /mnt/data/thlCopy the existing THL directory to the new directory location. For example:
shell> rsync -r /opt/continuent/thl/* /mnt/data/thl/Move the existing directory to a temporary location:
shell> mv /opt/continuent/thl /opt/continuent/old-thlCreate a symbolic link from the new directory to the original directory location:
shell> ln -s /mnt/data/thl /opt/continuent/thlRecover the host back into the cluster :
shell>cctrl -expert[LOGICAL:EXPERT] /alpha >datasource host1 recover
To change the THL location on a Primary:
Manually promote an existing Replica to be the new Primary:
[LOGICAL] /alpha > switch to host2
SELECTED SLAVE: host2@alpha
PURGE REMAINING ACTIVE SESSIONS ON CURRENT MASTER 'host1@alpha'
PURGED A TOTAL OF 0 ACTIVE SESSIONS ON MASTER 'host1@alpha'
FLUSH TRANSACTIONS ON CURRENT MASTER 'host1@alpha'
PUT THE NEW MASTER 'host2@alpha' ONLINE
PUT THE PRIOR MASTER 'host1@alpha' ONLINE AS A SLAVE
RECONFIGURING SLAVE 'host3@alpha' TO POINT TO NEW MASTER 'host2@alpha'
SWITCH TO 'host2@alpha' WAS SUCCESSFULUpdate the THL location as provided in the previous sequence.
Switch the updated Replica back to be the Primary:
[LOGICAL] /alpha > switch to host1
SELECTED SLAVE: host1@alpha
PURGE REMAINING ACTIVE SESSIONS ON CURRENT MASTER 'host2@alpha'
PURGED A TOTAL OF 0 ACTIVE SESSIONS ON MASTER 'host2@alpha'
FLUSH TRANSACTIONS ON CURRENT MASTER 'host2@alpha'
PUT THE NEW MASTER 'host1@alpha' ONLINE
PUT THE PRIOR MASTER 'host2@alpha' ONLINE AS A SLAVE
RECONFIGURING SLAVE 'host3@alpha' TO POINT TO NEW MASTER 'host1@alpha'
SWITCH TO 'host1@alpha' WAS SUCCESSFUL
To permanently change the directory currently holding the THL information can by reconfigured to a new directory location.
To update the location for a Replica by temporarily setting the Replica offline, updating the THL location, and re-enabling back into the cluster:
Shun the datasource and switch your node into the offline state using cctrl:
shell>cctrl -expert[LOGICAL:EXPERT] /alpha >datasource host1 shun[LOGICAL:EXPERT] /alpha >replicator host1 offline
Create a new directory, or attach a new filesystem and location on which the THL content will be located. You can use a directory on another filesystem or connect to a SAN, NFS or other filesystem where the new directory will be located. For example:
shell> mkdir /mnt/data/thlCopy the existing THL directory to the new directory location. For example:
shell> rsync -r /opt/continuent/thl/* /mnt/data/thl/Change the directory location using tpm to update the configuration for a specific host:
shell> tpm update --thl-directory=/mnt/data/thl --host=host1Recover the host back into the cluster :
shell>cctrl -expert[LOGICAL:EXPERT] /alpha >datasource host1 recover
To change the THL location on a Primary:
Manually promote an existing Replica to be the new Primary:
[LOGICAL] /alpha > switch to host2
SELECTED SLAVE: host2@alpha
PURGE REMAINING ACTIVE SESSIONS ON CURRENT MASTER 'host1@alpha'
PURGED A TOTAL OF 0 ACTIVE SESSIONS ON MASTER 'host1@alpha'
FLUSH TRANSACTIONS ON CURRENT MASTER 'host1@alpha'
PUT THE NEW MASTER 'host2@alpha' ONLINE
PUT THE PRIOR MASTER 'host1@alpha' ONLINE AS A SLAVE
RECONFIGURING SLAVE 'host3@alpha' TO POINT TO NEW MASTER 'host2@alpha'
SWITCH TO 'host2@alpha' WAS SUCCESSFULUpdate the THL location as provided in the previous sequence.
Switch the updated Replica back to be the Primary:
[LOGICAL] /alpha > switch to host1
SELECTED SLAVE: host1@alpha
PURGE REMAINING ACTIVE SESSIONS ON CURRENT MASTER 'host2@alpha'
PURGED A TOTAL OF 0 ACTIVE SESSIONS ON MASTER 'host2@alpha'
FLUSH TRANSACTIONS ON CURRENT MASTER 'host2@alpha'
PUT THE NEW MASTER 'host1@alpha' ONLINE
PUT THE PRIOR MASTER 'host2@alpha' ONLINE AS A SLAVE
RECONFIGURING SLAVE 'host3@alpha' TO POINT TO NEW MASTER 'host1@alpha'
SWITCH TO 'host1@alpha' WAS SUCCESSFUL