Hi Lionel,

Thank you for the reply.

I did try to increase the hive.server2.thrift.max.worker.threads to 1500 from 
the default 500 but it did not resolve the issue. Also we have 2 instances of 
Hive Server 2 running on different machines.

Could you recommend any other work around?

Thank you,
Karan Gupta

From: Lionel Liu <lionel...@apache.org>
Sent: Wednesday, April 11, 2018 10:34 AM
To: dev@griffin.incubator.apache.org; Karan Gupta <karan.gu...@tavant.com>
Subject: Re: Griffin Service Error

Hi Karan,

I've read your log again, found error happens as steps bellow:

1. You've configured hive.metastore.uris as 
 which is the correct one.
Griffin server start up and try to connect to hive metastore service, some 
error occurs:
2018-04-05 09:32:20.842  WARN 106074 --- [           main] hive.metastore       
                    : set_ugi() not successful, Likely cause: new client 
talking to old server. Continuing without it.
org.apache.thrift.transport.TTransportException: java.net.SocketException: 
Connection reset

But immediately, it succeed:
2018-04-05 09:32:20.843  INFO 106074 --- [           main] hive.metastore       
                    : Connected to metastore.

2. Griffin service will cache the hive table metadata, and refresh it every 15 
The first refresh happens when start up:
2018-04-05 09:32:23.248  INFO 106074 --- [pool-4-thread-1] 
o.a.g.c.m.hive.HiveMetaStoreService      : Evict hive cache

But it fails by this error:
2018-04-05 09:32:23.260 ERROR 106074 --- [pool-4-thread-1] hive.log             
                    : Got exception: 
org.apache.thrift.transport.TTransportException java.net.SocketException: 
Broken pipe (Write failed)
org.apache.thrift.transport.TTransportException: java.net.SocketException: 
Broken pipe (Write failed)

Griffin service logs this error in the cache refresh process, now the cache is 
evicted but new data fetch fails:
2018-04-05 09:32:23.263 ERROR 106074 --- [pool-4-thread-1] 
o.a.g.c.m.hive.HiveMetaStoreService      : Can not get databases : Got 
exception: org.apache.thrift.transport.TTransportException 
java.net.SocketException: Broken pipe (Write failed)
2018-04-05 09:32:23.263  INFO 106074 --- [pool-4-thread-1] 
o.a.g.c.m.hive.HiveMetaStoreService      : After evict hive cache,automatically 
refresh hive tables cache.

3. Then griffin service will try to reconnect to hive metastore asynchronously, 
but every time it tries to connect, the same error occurs:
2018-04-05 09:32:23.269  INFO 106074 --- [pool-3-thread-1] hive.metastore       
                    : Trying to connect to metastore with URI 
2018-04-05 09:32:23.279  WARN 106074 --- [pool-3-thread-1] hive.metastore       
                    : set_ugi() not successful, Likely cause: new client 
talking to old server. Continuing without it.
org.apache.thrift.transport.TTransportException: java.net.SocketException: 
Connection reset

But it also succeed to connect:
2018-04-05 09:32:23.280  INFO 106074 --- [pool-3-thread-1] hive.metastore       
                    : Connected to metastore.

4. And after 15 minutes, the same things happen again.

I think there are two problems we need to investigate:

1. Every time trying to connect hive metastore, error occurs but succeed 
I've googled this error message and found this: 
Seems like too many client connections to hive metastore service.

2. Every time griffin evict cache and try to fetch new data using the built 
connection last time, it was broken pipe, seems like the connection lasts too 
I wonder it could be solved by some configuration of hive metastore service, or 
it's also caused by too many connections.

Could you check about this? Hope it helps.


On Tue, Apr 10, 2018 at 8:57 PM, Karan Gupta 
<karan.gu...@tavant.com<mailto:karan.gu...@tavant.com>> wrote:
Hi Lionel,

hive.metastore.uris is correctly set as per my knowledge in the 
application.properties. Could you suggest any alternative or a work around?

Thank you,
Karan Gupta

From: Lionel, Liu <bhlx3l...@163.com<mailto:bhlx3l...@163.com>>
Sent: Tuesday, April 10, 2018 6:00 PM
To: Karan Gupta <karan.gu...@tavant.com<mailto:karan.gu...@tavant.com>>; 
Subject: RE: Griffin Service Error

Hi Karan,

It seems like connect hive metastore service fails, you need to configure 
"hive.metastore.uris” as the correct one in application.properties.

Lionel, Liu

From: Karan Gupta<mailto:karan.gu...@tavant.com>
Sent: 2018年4月10日 17:59
To: Lionel, Liu<mailto:bhlx3l...@163.com>
Subject: Griffin Service Error

Hi Lionel,

I am encountering the below error when I try to run the griffin service jar

Any guidance would be very helpful.

Thank you,
Karan Gupta
From: Vinod Raina
Sent: Monday, April 9, 2018 2:18 PM
To: Lionel, Liu <bhlx3l...@163.com<mailto:bhlx3l...@163.com>>
Cc: Karan Gupta <karan.gu...@tavant.com<mailto:karan.gu...@tavant.com>>
Subject: RE: Few Questions about Griffin

Thank you Lionel, this information helps ☺ ..

Vinod Raina | vinod.ra...@tavant.com<mailto:vinod.ra...@tavant.com>
Associate Technical Architect
M: +91 9711022965

From: Lionel, Liu <bhlx3l...@163.com<mailto:bhlx3l...@163.com>>
Sent: Saturday, April 7, 2018 1:32 PM
To: Vinod Raina <vinod.ra...@tavant.com<mailto:vinod.ra...@tavant.com>>; 
Cc: Karan Gupta <karan.gu...@tavant.com<mailto:karan.gu...@tavant.com>>
Subject: RE: Few Questions about Griffin

Hi Vinod,

For the first question, it looks like the validity dimension, to measure the 
data item by the rules defined. The validity dimension has not been implemented 
in griffin, but you can also make it work by profiling at current. For example, 
you can define the profiling rule as “select count(*) from source where 
len(telephone) = 10 and name is not null”, that will produce the count of items 
matched such a rule, with another metric as total count, then you’ll get the 
percentage. In fact, getting the count metrics is better than getting the 
percentage directly.
For the second question, I’m not very familiar with Kerberos, but in eBay, 
we’re also using hdfs cluster with Kerberos authentication. Griffin measure 
module works as a spark application, and it supports all the spark parameters, 
so it should work in the same way like you submit other spark applications on 
your cluster. If not correct pls tell me, thanks.

Lionel, Liu

From: Vinod Raina<mailto:vinod.ra...@tavant.com>
Sent: 2018年4月5日 13:09
To: Lionel Liu<mailto:lionel...@apache.org>; 
Cc: Karan Gupta<mailto:karan.gu...@tavant.com>
Subject: RE: Few Questions about Griffin

Thank you Lionel,
I have 2 more follow queries :

  1.  My requirement is to check the data quality in terms of whether the data 
confirms to the data types that I expect it to be. E.g One column may have 
telephone number, so I expect it to be 10 digit number , another column is 
birthdate, so I expect it to be in a date format or there is a name column and 
I don’t want it to be null/missing. So I need to create a metric report where I 
can get to see the percentage of data that confirms to the validations that we 
have created. Can griffin do that ?
  2.  Also, Our HDFS is a kerberised cluster. Can griffin work on a kerberised 
cluster ?

Vinod Raina | vinod.ra...@tavant.com<mailto:vinod.ra...@tavant.com>
Associate Technical Architect
M: +91 9711022965

From: Lionel Liu <lionel...@apache.org<mailto:lionel...@apache.org>>
Sent: Tuesday, April 3, 2018 2:16 PM
To: dev@griffin.incubator.apache.org<mailto:dev@griffin.incubator.apache.org>; 
Vinod Raina <vinod.ra...@tavant.com<mailto:vinod.ra...@tavant.com>>
Cc: Karan Gupta <karan.gu...@tavant.com<mailto:karan.gu...@tavant.com>>
Subject: Re: Few Questions about Griffin

Hi Vinod,

We're glad to receive your email, there're some other documents of Griffin 
listed below:
And you can follow 
 to try griffin docker image.

For your questions, I'll list my answers:

1. What is the usage of accuracy metric? In what situations, it will be useful?

Accuracy measures the match percentage between two data sources, we call them 
"target" and "source", "source" is the data source you trust, "target" is the 
data source you want to check.
For example, say "source" is [1, 2, 3, 4, 5], while "target" is [1, 3, 5, 7, 
9], we'll get the accuracy #(target items matched in source) / #(all target 
items) = 3/5 = 80%. Actually, "exactly match" is a narrow concept, in accuracy, 
we say "pass the match rule", users can define their own "match rule" like 
"source.age <= target.age AND upper(source.city) = upper(target.city)" instead 
of "exactly match".
When we have a data source we trust, let it be the "source", then we can 
measure accuracy of another data source named "target", to figure out how 
correctly we can trust.

There's a standard use case:
In our data pipeline, when we get users' data from site, we persist it as table 
T1, which we trust it as the source of truth. On the other hand, a copy of 
users' data will be pushed to some streaming or batch processes, after some 
steps, the processed data is persisted as table T2, we want to know how correct 
it is, or how much we can trust it.
Set T1 as "source", T2 as "target", we can get the accuracy of T2, with the 
wrong items from T2 persisted.

And another specific use case:
We have a streaming data process system, it consumes data from input and 
produces to output. In each output data item, it also contains the key of input 
item, we want to know how much data is successfully processed.
Set output as "source", input as "target", we can get the accuracy of input, 
and the missing items from input will be persisted.
Actually, this case measures the completeness of output, but it works like 
reversed accuracy, so we can use it like this.

However, in griffin measure configuration, the concept of source and target are 
based on the code implementation, which is different from the business concept 
above. In the documents of measure configuration, we're measuring accuracy of 
We are planning to modify the code implementation to be align with the business 
concept later, by then, we'll highlight it in the release notes.

2. Can we run other metrics using command-line? (or) Is only accuracy metric 
supported at the moment?

Yes, you can just run griffin measure module using cmd-line directly, like 
At current, griffin UI module doesn't support all the dimensions, but measure 
module supports accuracy, profiling, timeliness and uniqueness, you can get 
some description of them here: 

3. Project roadmap for features?

The project roadmap is out of date, we've updated it: 
Some new features we're planning in the short term planning:
- streaming measure job schedule.
- more data quality dimensions support, such as completeness, consistency, 
And for long term, maybe including:
- more data sources support, such as RDBs, elasticsearch.
- anomaly detection support.
- spark 2 support.

4. Can we use create custom Rules and profile existing data?

Yes, you can create custom rules for your data, according to the documents: 
The profiling rule supports simple spark-sql syntax directly, as 
If you want to use spark-sql, you can also define the rules like this: 

5. Postgresql and mysql -- both listed in Prerequisites. We have MySQL, Is that 

In fact, you can choose either one of postgresql and mysql.
We use mysql for the measure and schedule persistance before, but due to the 
license issue of release, we have to switch to postgresql these days.
If you want to use mysql, you need to modify some dependencies in service 
module and the application.properties file, rebuild the service.jar as well.
We are going to place a document to help users for mysql or other db.

Hope this helps you, please feel free if any question.


On Tue, Apr 3, 2018 at 1:41 PM, Vinod Raina 
<vinod.ra...@tavant.com<mailto:vinod.ra...@tavant.com>> wrote:
Hi Griffin team,
In our team, We are looking to create a Data Quality model for your EDL 
Ingestion and are exploring Apache Griffin for it. We have gone through the 
documentation. The documentation is still not complete but we understand that 
the project is in incubation and there might be other reasons as well.
It would be really helpful if there is any other source of information (other 
than the apache portal  and the git hub readme ) which can help us to 
understand the usage of this framework.
Also ,we have below few question and would really if you can help us with the 
answers :

1. What is the usage of accuracy metric? In what situations, it will be useful?
2. Can we run other metrics using command-line? (or) Is only accuracy metric 
supported at the moment?
3. Project roadmap for features?
4. Can we use create custom Rules and profile existing data?
5. Postgresql and mysql -- both listed in Prerequisites. We have MySQL, Is that 

Vinod Raina | 
Associate Technical Architect
M: +91 9711022965<tel:%2B91%209711022965>
Tavant Technologies | 
Okaya Centre, Tower 1, 5th Floor,B-5, Sector 62, Noida, UP 201 309

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