[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-16 Thread Bryan Call (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13277202#comment-13277202
 ] 

Bryan Call commented on TS-1238:


You can ignore the information about the average object size.  That was for 
disk cache.  I don't know what I was thinking at the time...

After a couple days the CFLUS is getting about the same cache hit ratio as LRU. 
 In a five minute period it is too hard to tell.  Sometimes it is better or 
worse by ~.1%.

It would be nice to have a stat for the number of times that cache fails to get 
a lock.  I would assume there are different locks for RAM and disk cache?  
Also, it is my understanding that if Traffic Server can't get a lock it will 
retry a configurable number of times and go to the origin server.  It might be 
nice to have a stat for when this happens too.


 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-15 Thread John Plevyak (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13276422#comment-13276422
 ] 

John Plevyak commented on TS-1238:
--

I think the problem is that the LRU cache doesn't account for its overhead, 
while the CLFUS cache does which puts it at an unfair disadvantage in terms of 
relative true memory used per byte allocated.  The CLFUS cache is much better 
behaved when the working set is larger than the RAM cache size and it supports 
compression.  I am going to commit this fix and leave CLFUS as the default and 
file another bug to fix the accounting for ram in the LRU cache.   I think this 
will make the performance comparable in the best case and better in worse cases.

 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-14 Thread Bryan Call (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13274771#comment-13274771
 ] 

Bryan Call commented on TS-1238:


I am running a patched version of 3.1.3 in production right now. It is busy 
filling up the ram cache.

Since we are already running 3.1.3 in production and using LRU, I thought it 
would be a better A/B test to patch 3.1.3 instead of using HEAD and introducing 
more variables.


 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-08 Thread Leif Hedstrom (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13270768#comment-13270768
 ] 

Leif Hedstrom commented on TS-1238:
---

Is this committed and fixed on trunk? Or are we pending more changes? I'm 
trying to get a handle on 3.1.4 release, so we can get a 3.2 release out 
soon...

 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-08 Thread John Plevyak (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13271042#comment-13271042
 ] 

John Plevyak commented on TS-1238:
--

It isn't committed.   Bryan was going to try it out.  It changes one of the
defaults (probably for the better) for RAM caching, but I wanted to give
him a chance to take a look.  I'll see if I can figure it out myself as
well.  It should be a very safe change.




 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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[jira] [Commented] (TS-1238) RAM cache hit rate unexpectedly low

2012-05-02 Thread Bryan Call (JIRA)

[ 
https://issues.apache.org/jira/browse/TS-1238?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13266717#comment-13266717
 ] 

Bryan Call commented on TS-1238:


I will coordinate the testing of the patch, but it might take a couple days.  I 
will shoot for Friday right now looking at my schedule.

I had a feeling that it might have to do with the seen filter since it doesn't 
take effect until the cache is full.  It might be nice to have a configuration 
option on how many hits you need before it is promoted to ram cache.  On some 
workings sets having this configured to 1 might be better.

 RAM cache hit rate unexpectedly low
 ---

 Key: TS-1238
 URL: https://issues.apache.org/jira/browse/TS-1238
 Project: Traffic Server
  Issue Type: Bug
  Components: Cache
Affects Versions: 3.1.3
Reporter: John Plevyak
Assignee: John Plevyak
 Fix For: 3.1.4

 Attachments: TS-1238-jp-1.patch


 The RAM cache is not getting the expected hit rate.  Looks like there are a 
 couple issues.

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