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From Michael Segel <michael_se...@hotmail.com>
Subject Re: How to make the client fast fail
Date Mon, 22 Jun 2015 18:22:10 GMT
Uhm… what happens when you hit a parameter that was made FINAL? 

;-) 

Yes, I agree that you can change some of the parameters at the application level. 
Using a timer thread is just as easy and you don’t have to worry about the fact that your
admins made certain parameters final in their configuration because of KISS. 

There are other reasons why you may want to use a timer thread… It really depends on what
you want to do and why.

> On Jun 16, 2015, at 1:08 PM, Bryan Beaudreault <bbeaudreault@hubspot.com> wrote:
> 
> I agree that more documentation would be better. However,
> 
> 
>> Yet, there are some applications which require a faster time out than
>> others. So, you tune some of the timers to have a fast fail, and you end up
>> causing unintended problems for others.
>> 
>> The simplest solution is to use threads in you client app. (Of course this
>> assumes that you’re capable of writing clean multi-threaded code and I
>> don’t want to assume anything.)
>> 
>> Remember that HBase is a shared resource. So you need to consider the
>> whole at the same time you consider the needs of one.
>> 
>> 
> This is not really true, it assumes a very naive configuration solution in
> which all processes are configured the same.  The default configs come from
> xml files, but are easily customized.  Consider:
> 
> Application A:
> 
> Configuration conf = HBaseConfiguration.create();
> conf.setInt("hbase.rpc.timeout", 8000);
> 
> // Operations on table have a timeout of 8s
> Connection conn = ConnectionFactory.createConnection(conf);
> conn.getTable("foo");
> 
> Application B:
> 
> // Operations on this table use default timeout
> Connection conn =
> ConnectionFactory.createConnection(HBaseConfiguration.create());
> conn.getTable("foo");
> 
> // Operations on this table use a very short timeout of 500ms
> Configuration conf = HBaseConfiguration.create();
> conf.setInt("hbase.rpc.timeout", 500);
> Connection shortConn = ConnectionFactory.createConnection(conf);
> short
> shortConn.getTable("foo");
> 
> Applications A and B are configured with different timeouts.  Further,
> Application B has two separate table connections, each with a different
> timeout.
> 
> The values are hardcoded above, but could easily be made configurable. The
> simplest of solutions uses System.getProperty(), so you can pass
> -Dmy.custom.timeout=500.  More complex solutions can utilize the various
> open source live configuration solutions. Such as netflix archaius, or
> hubspot's live-config -- both available on github.
> 
> Of course there can be unintended consequences if an application suddenly
>> starts to drop connections before a result or timeout occurs too.  ;-)
>> 
>> 
>>> On Jun 16, 2015, at 12:13 AM, lars hofhansl <larsh@apache.org> wrote:
>>> 
>>> Please always tell us which version of HBase you are using. We have
>> fixed a lot of issues in this area over time.Here's an _old_ blog post I
>> wrote about this:
>> http://hadoop-hbase.blogspot.com/2012/09/hbase-client-timeouts.html
>>> 
>>> Using yet more threads to monitor timeouts of another thread is a bad
>> idea, especially when the timeout is configurable in the first place.
>>> 
>>> -- Lars
>>>     From: mukund murrali <mukundmurrali9@gmail.com>
>>> To: user@hbase.apache.org
>>> Sent: Sunday, June 14, 2015 10:22 PM
>>> Subject: Re: How to make the client fast fail
>>> 
>>> It would be great if there is a single timeout configuration from the
>>> client end. All other parameters should fine tune based on that one
>>> parameter. We have modified simple based on trail basis to suit our need.
>>> Also not sure what side effect it would cause configuring those
>> parameters.
>>> 
>>> 
>>> 
>>> On Mon, Jun 15, 2015 at 10:38 AM, <Hariharan_Sethuraman@dell.com> wrote:
>>> 
>>>> We are also interested on the solution for this. With
>>>> hbase.client.retries.number = 7 and client.pause=400ms, it came down to
>>>> ~9mins (from 20 mins). Now we are thinking the 9mins is also a big
>> number.
>>>> 
>>>> Thanks,
>>>> Hari
>>>> 
>>>> -----Original Message-----
>>>> From: PRANEESH KUMAR [mailto:praneesh.sankar@gmail.com]
>>>> Sent: Monday, June 15, 2015 10:33 AM
>>>> To: user@hbase.apache.org
>>>> Subject: Re: How to make the client fast fail
>>>> 
>>>> Hi Michael,
>>>> 
>>>> We can have a monitoring thread and interrupt the hbase client thread
>>>> after time out instead of doing this I want the timeout or some
>> exception
>>>> to be thrown from the HBase client itself.
>>>> 
>>>> On Thu, Jun 11, 2015 at 5:16 AM, Michael Segel
>>>> wrote:
>>>> 
>>>>> threads?
>>>>> 
>>>>> So that regardless of your hadoop settings, if you want something
>>>>> faster, you can use one thread for a timer and then the request is in
>>>>> another. So if you hit your timeout before you get a response, you can
>>>> stop your thread.
>>>>> (YMMV depending on side effects... )
>>>>> 
>>>>>> On Jun 10, 2015, at 12:55 AM, PRANEESH KUMAR
>>>>>> 
>>>>> wrote:
>>>>>> 
>>>>>> Hi,
>>>>>> 
>>>>>> I have got the Connection object with default configuration, if the
>>>>>> zookeeper or HMaster or Region server is down, the client didn't
>>>>>> fast
>>>>> fail
>>>>>> and it took almost 20 mins to thrown an error.
>>>>>> 
>>>>>> What is the best configuration to make the client fast fail.
>>>>>> 
>>>>>> Also what is significance of changing the following parameters.
>>>>>> 
>>>>>> hbase.client.retries.number
>>>>>> zookeeper.recovery.retry
>>>>>> zookeeper.session.timeout
>>>>>> zookeeper.recovery.retry.intervalmill
>>>>>> hbase.rpc.timeout
>>>>>> 
>>>>>> Regards,
>>>>>> Praneesh
>>>>> 
>>>>> 
>>>> 
>>> 
>>> 
>> 
>> 

The opinions expressed here are mine, while they may reflect a cognitive thought, that is
purely accidental. 
Use at your own risk. 
Michael Segel
michael_segel (AT) hotmail.com






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