/Programs ODB tree
Links
Purpose
The ODB /Programs tree contains user and system information related to client programs.
Creating the /Programs tree
The /Programs ODB tree is created by the system. It contains
- key Execute on start run
- key Execute on stop run
- a subdirectory for each client that runs on the experiment, created by the system the first time a client runs
Each client will have its own subtree in the /Programs tree. The subtree will be named for the client, and contains system information as well as task-specific characteristics, such as the watchdog timeout, and a number of optional features, such as a commands to start the task, alarm condition etc.
Example of /Programs tree
The following is an example of the /Programs tree from an experiment obtained with the odbedit ls command :
[local:bnmr:S]/>ls -lt /programs
Key name Type #Val Size Last Opn Mode Value --------------------------------------------------------------------------- Execute on start run STRING 1 256 18h 0 RWD /home/bnmr/online/bnmr/bin/at_start_run.csh Execute on stop run STRING 1 256 18h 0 RWD /home/bnmr/online/bnmr/bin/at_end_run.csh ODBEdit DIR Logger DIR Epics DIR rf_config DIR mheader DIR Mdarc DIR autorun DIR feBNMR DIR camplog DIR Lcrplot DIR mhttpd DIR mdump DIR Speaker DIR mdarc_cleanup DIR
The following example shows the subdirectory for the mlogger client:
[local:bnmr:S]/>ls -lt /programs/logger Key name Type #Val Size Last Opn Mode Value --------------------------------------------------------------------------- Required BOOL 1 4 4h 0 RWD y Watchdog timeout INT 1 4 4h 0 RWD 10000 Check interval DWORD 1 4 4h 0 RWD 180000 Start command STRING 1 256 4h 0 RWD mlogger -D Auto start BOOL 1 4 4h 0 RWD n Auto stop BOOL 1 4 4h 0 RWD n Auto restart BOOL 1 4 4h 0 RWD y Alarm class STRING 1 32 4h 0 RWD Caution First failed DWORD 1 4 4h 0 RWD 1259294464
Keys in the /Programs ODB tree
Execute on start run
- Type: STRING
- Default: ""
This key in the /Programs ODB tree may contain a command or script to be executed on a START transition.
Execute on stop run
- Type: STRING
- Default: ""
This key in the /Programs ODB tree may contain a command or script to be executed on a STOP transition.
<client-name> subtree
- Type: DIR
This subdirectory in the /Programs ODB tree is repeated for each client that has been run on the experiment, whether MIDAS utilities or user-written frontends. The subtree will be named for the client.
Required
- Type: BOOL
- Default: "n"
If this key in the <client-name> subtree is set to "y", this client is designated as required.
It should be combined with setting Auto start and/or Auto restart to "y", and supplying a Start command. If set to "n", the run will start successfully without this client running. Note that this field also changes the display in the mhttpd Programs page.
A run will be prevented from starting if this client is not running providing the Prevent start on required program key is also set.
This key should be set to "y" for essential programs only; typically the logger and all front-end programs should be required programs.
Watchdog timeout
- Type: INT
- Default: 10000
This key in the <client-name> subtree contains the the watchdog timeout set in milliseconds. A watchdog runs automatically checking (every Check interval ms) whether the client responds. If the client has not been responded for Watchdog timeout ms, the client will be assumed to have timed out, and it will be killed. The watchdog time for each client should be adjusted as required. For example, clients that contact external hardware that is slow to respond should have a longer time set, or they may time out before the operation is complete.
Check interval
- Type: DWORD
- Default: 180000
This key in the <client-name> subtree contains the time interval in milliseconds that the Watchdog checks the client to see if it is responding. See Watchdog timeout.
Start command
- Type: STRING
- Default: ""
This key in the <client-name> subtree optionally contains the command used to restart the client. It is required if either Auto start or Auto restart is set to "y", or the user wishes to start or restart the client using the mhttpd restart button on the Programs page. If no start command is supplied, the user can restart the client by hand.
Auto start
- Type: BOOL
- Default: "n"
If this key in the <client-name> subtree is set to "y", the client will be started automatically using the Start command. This will occur when an experiment is first started after killing all clients. If the client then dies (or times out - see |Watchdog timeout) the client will not be restarted unless Auto restart is set to "y".
Auto stop
- Type: BOOL
- Default: "n"
If this key in the <client-name> subtree is set to "y", the client will be automatically shut down on a STOP transition.
Auto restart
- Type: BOOL
- Default: "n"
If this key in the <client-name> subtree is set to "y" the client will be restarted automatically using the Start command. This will occur if the client dies or times out (see |Watchdog timeout). If set to "n", the client must be restarted by the user. See also Auto start.
Alarm class
- Type: STRING
- Default: ""
If this key in the <client-name> subtree is set to one of the existing alarm classes, an entry in the /Alarms ODB tree will be automatically created for this program. The Alarm Type will be Program alarm . This will cause an alarm to go off if the program is not running (provided both the Alarm System is enabled, and the individual alarm enabled).
If the Prevent start on alarms is also set to "y", the run will be prevented from starting if an alarm has been triggered.
First failed
- Type: DWORD
- Default: ""
This key in the <client-name> subtree is filled by the System to indicate when the client first failed.