Question about concurrent requests and error management

[Richard Thibault]

Hello,

I know that my underlying server can handle 10 queries at the same time, but I don't wan't to generate errors to my users : I would prefer to stack queries that are above these 10 queries.
Is it possible to use mod_qos to do that ?

Thank you for your answer.
Best regards.

[Pascal Buchbinder]

You can use QS_SrvSerialize to achieve this when combining it with QS_EventRequestLimit.

Example:

QS_SrvSerialize       on

# queue size is 500
QS_EventRequestLimit  LimitLocation 500
# max. 20 concurrent
SetEnvIfPlus          REQUEST_URI /serialize SerialLimtCfg=19
# enable counter
SetEnvIfPlus          REQUEST_URI /serialize LimitLocation=on
<Location /serialize>
  # serialize when currency counter exceeds 19
  QS_SetEnvIfCmp      QS_EventRequestLimit_LimitLocation_Counter gt SerialLimtCfg QS_SrvSerialize=1
</Location>

[Pascal Buchbinder]

Update: I've edited the example (first line was the wrong directive).

[Richard Thibault]

Fantastic !
I would not have found the solution on my own, because I didn't know SerialLimtCfg and QS_EventRequestLimit_LimitLocation_Counter !
Thank you !

[Richard Thibault]

I just have a question to precise the use of the serialization : is the serialization quue global or per Location ?
If it's per Location, it means that the variable SerialLimtCfg can be defined per Location ?

[Pascal Buchbinder]

There is only one single queue for QS_SrvSerialize.