eCAP

How does Squid does not block on eCap adapter to finish processing

Asked by Jatin on 2014-04-30

Hello,

My eCap adapter performs various checks on the request and response which may take some time to process. Usually less than a second.

1) I would like to understand that does Squid blocks until eCap adapter finishes processing the transaction.
(If Squid does not block on eCap to return then how does eCap notify Squid of completion of a transaction)

2) If Squid does not block on eCap would it mean that eCap along with Squid should be able to process thousands of requests per second.

Thanks

Question information

Language:: English Edit question

Status:: Solved

For:: eCAP Edit question

Assignee:: No assignee Edit question

Solved by:: Alex Rousskov

Solved:: 2014-05-01

Last query:: 2014-05-01

Last reply:: 2014-05-01

Link existing bug

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Alex Rousskov (rousskov) said on 2014-05-01:

All eCAP calls are blocking. For example, the host transaction will wait for the host::Xaction::noteVbContentAvailable() method call to return.

Some host applications may be threaded or use multiple processes to avoid blocking the entire host application while waiting for a single eCAP transaction.

It is also possible to implement so called "asynchronous" adapters that work in parallel with the host application even if the host application does not use multiple threads or processes. For documentation, please see doc/async.txt. Asynchronous adapters are supported since libecap v1.0.0. Writing correct asynchronous code is very difficult so use this approach only if necessary and only after you got the basic blocking functionality working well.

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Jatin (jbhasin83) said on 2014-05-01:

Production squid version does not support libecap v1.0.0. So does the trunk version which supports libecap v1.0 would support "asynchronous" calls with my adapter ?

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