RWAST state

[Sk Noorul Hassan]

During Duty server switch over, one of the application process who is responsible for talking to two other standby servers has gone to MWAIT(RWAST) state. As a result other stanby server could not establish connection with new duty server resulting in two duty case. Is there any specific reason behind a process goes to RWAST state ? Pls suggest

[Volker Halle · Accepted solution]

Hi,

there are many possible problems leading to a process entering RWAST state.

Please see the 2 TIMA articles referenced in the 1-APR-2006 entry of:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1015664

for troubleshooting guidelines.

Volker.

[comarow]

To get you started, first do not try to stop the process. Not only will you not be able to, but it will prevent all analysis.

Go into SDA and do a show sum.
SDA>show sum
find the index number
then set the process to that index nmber
SDA>set proc/index=indexnumber
SDA>do a show process

If the top has a delete pending, there is
nothing more you can do, as someone has
already tried to stop it. No further diagnose is possible. You can't stop the processes, as stopping a process queues up an AST. Since it is waiting for AST, it will never be delivered.

Otherwise, look at the bytlm and see if you have any left. If you have Ability Manager (free!) you can fix that. There are some other unsupported tools.

If not, it's probably an I/O that has not completed.

SDA>show process/channel
and you can see all the I/Os. It is
*probably* the channel marked busy. See if other processes are able to use it.

You can get an unsupported tool to free it. By unsupported we mean it may crash the system.

Best of luck.

[Arch_Muthiah]

Sk,

RWAST indicates the wait is expected to be satisfied by the delivery and/or enqueuing of an AST to the process.

Reasons for a pocess endup with RWAST state are...
-- waiting for an I/O to complete on a channel or
-- running out of a process or system quota or
-- waiting for a file system or lock request to complete or
-- waiting for a subprocess to terminate

Processes in the RWAST state can NOT be deleted until the condition they are waiting for is met. If you can not identify what the process is waiting for, you will have to reboot the system to eliminate the process.

Archunan

[Arch_Muthiah]

Sk,

you can use these cmnds to get more details about the process in RWAST state.

$ analyze/system
sda> read/executive
sda> read sys$loadable_images:sysdef
sda> sho summary

it will display the particular process's index, using that index there is a way to troubleshoot this process.


Archunan