php daemon

[mark_kccs]

Hi to all

I need to create script that will loop continuously which I believe could be now as a daemon. The purpose is to query a db for new messages that will need to be sent. My initial thinking is to either wrap the script in an infinate while loop or call a function recursively. My concerns are how to handle the following;

monitor if the daemon is running or crashed
restart daemon if the previous event has occured handling the cause
do i need to address multi-threading?
memory management
manually restarting and stopping

I would greatly appeciate any input or pointers.

Many thanks in advance.

[shamly]

The PHP script needs to be running in the commandline. Create a cron script to check the last update time of a dummy text file. Update the dummy text file every one minute or so. This way if the file is not updated for sometime you can assume that there is some problem with the daemon.

The daemon can be killed using ps ax | grep php if I am not mistaken. Using this you can kill the script and restart it.

[dagon]

do you really need a daemon? wouldn't a cron job do? I have done both but the latter is much easier to maintain.

[Kudose]

I agree with Dagon ... unless the system needs to be real time, a cron job would be the better choice.

[Weedpacket]

Some DBMSs also provide a management interface for scheduling regular tasks related to the database (or the DBMS itself).

They could, for example, be set up to check every minute or so for new records, and run a script to send emails when it finds some. No additional monitoring is then required.

It may be further possible to have the DBMS run the script immediately when the new record is added, by having an insert trigger attached to the table that runs a stored procedure. No additional monitoring or scheduling is then required.

All this depends on what DBMS you're using, of course. Consult its documentation to see if and how you can use it this way.