Re: Semaphore Error

rushik wrote:

>
> We are using a huge business application running on LAMP. For database
> operations we are maintaining centralized DB manager classes in php
> which perform all the single table related activity. Before inserting
> new record we are acquiring semaphore on specific key (all the tables
> are having seprate sem keys), insert the record and release the
> semaphore.
>

Why? MySQL is quite capable of isolating DML operations.

>>>From past few days we are getting error "Warning: sem_get()
> [function.sem-get]: failed for key ___: No space left on device", i've
> gone to linux console check thru ipcs command whether semaphore is
> there or not ?? ___ sem was there i've removed that by ipcrm, it
> started working.
>

(/me does not like IPC)

How many semaphores have you got in use? It might be useful to include (a
sample of) the output of ipcs or 'cat /proc/sysvipc/shm'. AIR there are
hard limits compiled into the kernel.

> Now the problem is, I m acquiring sem on key say 774, then i m not able
> to use sem keys 775, 776, 777 etc, I really dont know the reason.
>

eh? I've only seen mapping filenames to keys using ftok.

HTH

C.
.