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Queue with cflock on Coldfusion 9

We ran into a problem with our event gateways as we upgraded from ColdFusion 8 Enterprise to ColdFusion 9 Enterprise.

We have an event gateway setup to establish a connection to a third party. They updated us at least every 10 seconds, and sometimes many times per second.

We have a Java class configured as an Event Gateway listener, and it passes events and data to the CFC function. In this function, we actually use the name <cflock>to ensure that requests are processed in order and requests will be queued at this point to have exclusive access to the named lock. This lock has a timeout of 30 seconds.

I also have a lot of debugging in this function, and I noticed a few things:

  • Requetst will queue before the tag <cflock>, waiting for blocking, and this queue can exceed 40 events
  • All requests are processed when they receive a lock for 6 seconds. The average time is from 1.5 to 2 seconds when they receive a lock when they complete processing.

So the problem is that from time to time I will have a lock timeout, and that is after 30 seconds. First, I register if the request is waiting for a lock. It looks like this:

"Information","Thread-23","06/23/10","15:45:18","APP1","F4B42A5A-F34D-C614-DE01B150E6906F78 (1277304318606) : PRE LOCK"

And then further down the logs I see this for the same query:

"Error","Thread-23","06/23/10","15:45:48","APP1","F4B42A5A-F34D-C614-DE01B150E6906F78 (1277304348607) : LOCK ERROR: A timeout occurred while attempting to lock lock_ResponseDispatcher."

After 30 seconds in between. Requests and any event data associated with it are lost at this stage. Not good.

So, I thought I'd see if the queue was handled enough. I'm not sure how events are queued <cflock>. Is there a hard limit?

, , :

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Ciaran

+3
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CFC:

component {

    public void function onIncomingMessage (required struct msg) {

        var sys = createObject("java", "java.lang.System");
        var tag = createUUID();
        var logFile = "test\gatewaytest";

        writelog (file=logFile, text="#tag# - about to queue");

        try {

            lock name="myTestLock" timeout="120" {
                writelog (file=logFile, text="#tag# - got lock");

                thread action="sleep" duration="5000"; //ms 
            }

            writelog (file=logFile, text="#tag# - released lock");

        } catch (any e) {
            writelog (file=logFile, text="#tag# - ERROR - #e.message#");
        }
    }
}

(2 ) . , .

- CFML "TestGW", CFC .

script , :

<cfset msg = {mymessage = "hello gateway"} />
<cfset sendGatewayMessage("TestGW", msg) />

1 - :

1, , :

"Information","Thread-17","06/25/10","10:32:09",,"50805BB4-1C23-9073-67A70A86CA6F8E54 - about to queue"
"Information","Thread-17","06/25/10","10:32:09",,"50805BB4-1C23-9073-67A70A86CA6F8E54 - got lock"
"Information","Thread-17","06/25/10","10:32:14",,"50805BB4-1C23-9073-67A70A86CA6F8E54 - released lock"
"Information","Thread-17","06/25/10","10:32:14",,"50811F1A-1C23-9073-67AD3E9C0BF2000C - about to queue"
"Information","Thread-17","06/25/10","10:32:14",,"50811F1A-1C23-9073-67AD3E9C0BF2000C - got lock"
"Information","Thread-17","06/25/10","10:32:19",,"50811F1A-1C23-9073-67AD3E9C0BF2000C - released lock"
"Information","Thread-17","06/25/10","10:32:19",,"5081E27F-1C23-9073-67B5D2EF6AED8426 - about to queue"
"Information","Thread-17","06/25/10","10:32:19",,"5081E27F-1C23-9073-67B5D2EF6AED8426 - got lock"
"Information","Thread-17","06/25/10","10:32:24",,"5081E27F-1C23-9073-67B5D2EF6AED8426 - released lock"
"Information","Thread-17","06/25/10","10:32:24",,"5082A5E1-1C23-9073-674E9467F395686F - about to queue"
"Information","Thread-17","06/25/10","10:32:24",,"5082A5E1-1C23-9073-674E9467F395686F - got lock"
"Information","Thread-17","06/25/10","10:32:29",,"5082A5E1-1C23-9073-674E9467F395686F - released lock"

- . , .

2 - :

5, , :

"Information","Thread-18","06/25/10","11:26:01",,"526CC05B-C9E1-FADE-73CE3426BC0A3F92 - about to queue"
"Information","Thread-18","06/25/10","11:26:01",,"526CC05B-C9E1-FADE-73CE3426BC0A3F92 - got lock"
"Information","Thread-27","06/25/10","11:26:01",,"526CD0EB-049E-D382-2C3A7E3C0DBF8ED3 - about to queue"
"Information","Thread-21","06/25/10","11:26:02",,"526CDEED-C2B3-3C92-0F57CFA317AC02F8 - about to queue"
"Information","Thread-20","06/25/10","11:26:02",,"526CEE25-F25B-890C-F7501B5489C6BB21 - about to queue"
"Information","Thread-25","06/25/10","11:26:02",,"526CFD3C-EAFD-40E7-EBA2BE59B87D5936 - about to queue"
"Information","Thread-24","06/25/10","11:26:03",,"526D0FC5-E5E2-642E-452636C8838ADE33 - about to queue"
"Information","Thread-26","06/25/10","11:26:03",,"526D1096-C82E-535B-36D57D3A431D1436 - about to queue"
"Information","Thread-23","06/25/10","11:26:03",,"526D1F9C-9A9C-FA84-E153A944123E77BE - about to queue"
"Information","Thread-19","06/25/10","11:26:04",,"526D2EDC-EA54-4D83-3F6BB681A5CCAA89 - about to queue"
"Information","Thread-22","06/25/10","11:26:04",,"526D3F09-073F-2B0C-E94652D1C95B09CB - about to queue"
"Information","Thread-18","06/25/10","11:26:06",,"526CC05B-C9E1-FADE-73CE3426BC0A3F92 - released lock"
"Information","Thread-22","06/25/10","11:26:06",,"526D3F09-073F-2B0C-E94652D1C95B09CB - got lock"
"Information","Thread-22","06/25/10","11:26:11",,"526D3F09-073F-2B0C-E94652D1C95B09CB - released lock"
"Information","Thread-27","06/25/10","11:26:11",,"526CD0EB-049E-D382-2C3A7E3C0DBF8ED3 - got lock"
"Information","Thread-27","06/25/10","11:26:16",,"526CD0EB-049E-D382-2C3A7E3C0DBF8ED3 - released lock"
"Information","Thread-19","06/25/10","11:26:16",,"526D2EDC-EA54-4D83-3F6BB681A5CCAA89 - got lock"
"Information","Thread-19","06/25/10","11:26:21",,"526D2EDC-EA54-4D83-3F6BB681A5CCAA89 - released lock"

UUID 526D3F09-073F-2B0C-E94652D1C95B09CB. , , . Hoever, , - 526CD0EB-049E-D382-2C3A7E3C0DBF8ED3, .

:

, , cflock . , , , - - .

, cflock !

, , .

, .

+2

, FIFO LIFO; :

30 . . .

CFLock throwOnTimeout, true. false, , , . , - :

<cfset made_it_through_lock = false />
<cflock name="single_threaded_lock_name" throwOnTimeout="false">
    <!--- ... do stuff ... --->
    <cfset made_it_through_lock = true />
</cflock>
<cfif made_it_through_lock eq false>
    <!--- 
          log the event data that you don't want to lose, then abort, 
          setting the necessary http status code & headers
    --->
</cfif>
+1

Source: https://habr.com/ru/post/1751421/

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