Transaction Settings

Click the Magnify icon to view the NAS Administrator.

A NAS Administrator maintains one logical volume and its restart data for each kjs. A logical volume is made up of one or more physical volumes. A physical volume stores the state of all ongoing transactions. If you have more than one physical volume, additional physical volumes are mirrors of the first physical volume.

restart and restart.bak

When initially starting NAS, NAS identifies the location of an empty log file for each kjs where NAS writes information about the state of all ongoing distributed transactions for that process. NAS then creates additional files called restart and r estart.bak (a backup of restart ) for each kjs. These files record the location of the log file and the state of the logical and physical volumes. Once created, NAS refers to the restart file for the location and state of the log file each time the server restarts. NAS stores the restart and restart.bak in the root and mirror directories listed on the Configuration tab.

These files should be stored on different devices if possible. If both restart and restart.bak become corrupted, the transaction manager becomes inoperable and the administrator must cold start the server. When cold starting a server, NAS looks to the registry for the location of the log file and overwrites the existing log file.

Transaction Log File Configuration

Log files can be either raw partitions or simple files. The install program creates file system based on logs only. The default size of transaction logs is 4 megabytes on a Solaris system.

Transaction Log Maintenance

The transaction monitor periodically checks the logs and discards old transactions that are complete. This service is built into the transaction monitor and is not configured.

Disk Configuration

The left pane of the Transaction screen displays a tree of nodes. The first level shows a registered NAS server, and the second level displays engine nodes. There is one engine node for each running kjs. Only Java engines (kjs) appear in the tree because only kjs engines support transactions.

Physical Volume Properties

The third level of the tree displays the physical volumes for each process. Click on the icon for more detail. The page size of a page used in the transaction manger, the total size of the physical volume, and the amount of unused disk space in the physical volume is shown. You cannot edit these values.

Disk Properties

The fourth level of the tree displays disk properties. A disk can be thought of as a partition of the physical volume. You can create an unlimited number of disks, but you cannot delete a disk after it is created. Click on the disk node icon to display the location and size of the selected disk.