5.0.65
Mac OS X Server

On 3/4/05 10:53 AM, "Chuck Lockwood" <[EMAIL PROTECTED]> wrote:

> Roland,
> 
> What version and build of Witango are you using?
> 
> Chuck Lockwood
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> LockData Technologies, Inc.
> 309 Main Avenue, Hawley, Pa 18428
> 570-226-7340 ~ Fax: 570-226-7341
> [EMAIL PROTECTED] ~ www.lockdata.com
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  
> -----Original Message-----
> From: Roland Dumas [mailto:[EMAIL PROTECTED]
> Sent: Thursday, March 03, 2005 6:45 PM
> To: [email protected]
> Subject: Re: Witango-Talk: Baling wire and duct tape to prevent crashing
> 
> Unfortunately, even with datasource connections being immortal, the CPU
> usage for witangod is climbing to 60% and upward. There's something else
> that's going on in witango that's unhappy.
> 
> 
> On 3/3/05 11:20 AM, "Roland Dumas" <[EMAIL PROTECTED]> wrote:
> 
>> Ok, not yet figured out why one machine clone crashes while the other
>> doesn't, but am trying to patch each part of ODBC without taking
> production
>> machine out of service. (It's a very productive ecommerce site)
>> 
>> What we've figured out:
>> 
>> When witango gets a hit that requires a connection to mysql, it looks for
> an
>> available connection using that DSN. If it's available, it uses it.
>> 
>> If there are current connections, but they're busy, it spawns another
>> 
>> A pile of hits at the same moment creates a small stack of data
> connections.
>> Up to 8. 
>> 
>> Subsequently, when traffic is slower, witango picks one of the data
>> connections and lets the others age. Don't know how it picks one vs
> another,
>> but that's what it does. That leaves the others aging out and should
> expire
>> when they hit the datasourcelife setting.
>> 
>> That's where the trouble comes. Rather than die, the connections get hung
>> up, cause CPU usage to jack up, eventually cause new hits to get hung and
>> the witango server crashes. When they're tied up, they aren't available to
>> be used, but are technically alive, I guess, because if witango has
> selected
>> one of those, visitors get hung up.
>> 
>> So, after updating this piece and that piece of ODBC, it still does the
> same
>> thing and JDBC has its own profile of random crashes.
>> 
>> So, while we sift though the finger-pointing and terse instructions, we've
>> jury rigged a way to prevent crashes.
>> 
>> On another witango server, we've created a cron to hit the sick server
> every
>> hour with 8 <@URL>s that each hit a database. That makes sure that the 8
>> connection requests are simultaneous and generate 8 connections. The
>> connections are alive, but aging, these 8 refresh them all. The counter
> goes
>> back to 1. 
>> 
>> Then, we set the datasource life to 24 hours. That gives the cron 24
>> opportunities to restart the timer on every datasource.
>> 
>> Seems to be working.
>> 
>> Net net: if datasource expiry is causing crashes, don't ever let one
> expire.
>> 
>> 
>> 
>> 
>> 
>> 
>> -----------------------------------------
>> Roland Dumas
>> Roberts Information Services
>> 310 W. Bellevue Avenue
>> San Mateo CA 94402
>> 650-347-1373
>> 415-412-9300 (cell)
>> [EMAIL PROTECTED]
>> SMS: http://new.servqual.com/html/sms.tml
>> 
>> 
>> ________________________________________________________________________
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>> 
> 
> 
> -----------------------------------------
> Roland Dumas
> Roberts Information Services
> 310 W. Bellevue Avenue
> San Mateo CA 94402
> 650-347-1373
> 415-412-9300 (cell)
> [EMAIL PROTECTED]
> SMS: http://new.servqual.com/html/sms.tml
> 
> 
> ________________________________________________________________________
> TO UNSUBSCRIBE: Go to http://www.witango.com/developer/maillist.taf
> 
> 
> 
> 
> ________________________________________________________________________
> TO UNSUBSCRIBE: Go to http://www.witango.com/developer/maillist.taf
> 


-----------------------------------------
Roland Dumas
Roberts Information Services
310 W. Bellevue Avenue
San Mateo CA 94402
650-347-1373
415-412-9300 (cell)
[EMAIL PROTECTED]
SMS: http://new.servqual.com/html/sms.tml


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