Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Plain View
Flume, mail # user - Lock contention in FileChannel


+
Pankaj Gupta 2013-08-13, 23:13
+
Hari Shreedharan 2013-08-13, 23:39
+
Pankaj Gupta 2013-08-14, 00:01
+
Hari Shreedharan 2013-08-14, 00:14
+
Brock Noland 2013-08-14, 00:51
+
Pankaj Gupta 2013-08-14, 02:06
+
Hari Shreedharan 2013-08-14, 02:18
+
Brock Noland 2013-08-14, 02:22
+
Pankaj Gupta 2013-08-14, 02:33
+
Brock Noland 2013-08-14, 02:41
+
Pankaj Gupta 2013-08-14, 02:46
+
Brock Noland 2013-08-14, 02:54
+
Pankaj Gupta 2013-08-14, 02:57
+
Brock Noland 2013-08-14, 03:06
+
Pankaj Gupta 2013-08-14, 03:16
+
Brock Noland 2013-08-14, 03:30
+
Pankaj Gupta 2013-08-14, 18:57
+
Pankaj Gupta 2013-08-14, 19:12
+
Pankaj Gupta 2013-08-14, 19:34
+
Hari Shreedharan 2013-08-14, 19:43
+
Pankaj Gupta 2013-08-14, 19:59
+
Pankaj Gupta 2013-08-15, 06:04
+
Pankaj Gupta 2013-08-18, 04:43
Copy link to this message
-
Re: Lock contention in FileChannel
Hari Shreedharan 2013-08-14, 19:04
Looks like your channel is able to write a huge number of events but reads
are slow - which does seem like it is an issue with whatever is taking the
events (the channel does more work to write than read - more data is
written to disk and more data is fsycned). One thing I noted only now is
that you are using load balancing sink processors for your sinks - which
means only one sink configured in the sink processor's group is active at
any point in time - no matter how many sinks are in that group. You might
want to increase the number of sink groups or remove the sink groups
altogether, so all sinks can poll the channel at the same time.
On Wed, Aug 14, 2013 at 11:57 AM, Pankaj Gupta <[EMAIL PROTECTED]>wrote:

> I tried increasing the dataDirs to 2 and 4 per disk but doesn't seem to
> help much. I then replaced the avro sink with null sinks and events are
> still filling up in the channel. I tried with both 2 and 4 dataDirs per
> disk and null sink, still don't get throughput higher than 1.5 MBps.
>
>
> On Tue, Aug 13, 2013 at 8:30 PM, Brock Noland <[EMAIL PROTECTED]> wrote:
>
>> Increasing the number of file channels will result in more checkpoints.
>> Therefore there will be more io than simply increasing the number of
>> dataDirs.  However, this might be a case where it'd be nice to relax the
>> file channel data consistency constraints a little to get increased
>> throughput. That feature does not exist at present.
>>
>>
>> On Tue, Aug 13, 2013 at 10:16 PM, Pankaj Gupta <[EMAIL PROTECTED]>wrote:
>>
>>> I did try increasing number of FileChannels. At 2 FileChannels per disk
>>> performance seemed to be 25% better. At 4 FileChannels per disk performance
>>> dropped to even below 1 FileChannel per disk. I will try increasing the
>>> dataDirs tomorrow.
>>>
>>>
>>> On Tue, Aug 13, 2013 at 8:06 PM, Brock Noland <[EMAIL PROTECTED]>wrote:
>>>
>>>> dataDirs is a comma separated list. Try 3-4 directories and then the
>>>> same test.
>>>> On Aug 13, 2013 9:58 PM, "Pankaj Gupta" <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> Both disks were at around 15-25%.
>>>>>
>>>>>
>>>>> On Tue, Aug 13, 2013 at 7:54 PM, Brock Noland <[EMAIL PROTECTED]>wrote:
>>>>>
>>>>>> Gotcha. When you run tge test what is tye disk utilization
>>>>>> percentage? Iostat can be used for this.
>>>>>> On Aug 13, 2013 9:47 PM, "Pankaj Gupta" <[EMAIL PROTECTED]>
>>>>>> wrote:
>>>>>>
>>>>>>> Those are the boxes we want to collect data from. They run flume and
>>>>>>> send data through their avro sinks to the avro source on this box. We are
>>>>>>> getting data at a pretty good rate and the problem is in fact that the
>>>>>>> events don't drain from the FileChannel fast enough and the channel fill
>>>>>>> percentage keeps getting higher.
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Aug 13, 2013 at 7:41 PM, Brock Noland <[EMAIL PROTECTED]>wrote:
>>>>>>>
>>>>>>>> What is sending the events to the avro source?
>>>>>>>> On Aug 13, 2013 9:34 PM, "Pankaj Gupta" <[EMAIL PROTECTED]>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Here's the config:
>>>>>>>>> # define channels, one for each disk
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> agent1.channels.ch1.type = FILE
>>>>>>>>> agent1.channels.ch1.checkpointDir = /flume1/checkpoint
>>>>>>>>> agent1.channels.ch1.dataDirs = /flume1/data
>>>>>>>>> agent1.channels.ch1.maxFileSize = 375809638400
>>>>>>>>> agent1.channels.ch1.capacity = 75000000
>>>>>>>>> agent1.channels.ch1.transactionCapacity = 4000
>>>>>>>>>
>>>>>>>>> agent1.channels.ch2.type = FILE
>>>>>>>>> agent1.channels.ch2.checkpointDir = /flume2/checkpoint
>>>>>>>>> agent1.channels.ch2.dataDirs = /flume2/data
>>>>>>>>> agent1.channels.ch2.maxFileSize = 375809638400
>>>>>>>>> agent1.channels.ch2.capacity = 75000000
>>>>>>>>> agent1.channels.ch2.transactionCapacity = 4000
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> # Define an Avro source named avroSource1
>>>>>>>>> # Each sink can connect to only one channel.
>>>>>>>>> # Connect it to channel ch1. Load balance it to 2 avroSinks
>
+
Pankaj Gupta 2013-08-14, 02:16