Hi all,
I want to add some dynamic behavior to my observer cp, say:
postPut(){
if(flag) {do function1()};
else {do function2()}
}
Is there a way to dynamically change the value of flag? One Feasible
approaches is to change a value in table descriptor, but then I need to
restart the tab
RE: passing a parameter to an observer coprocessor
>>
>> Add fake cf + column to your Put operation
>>
>> Put put = new Put(row);
>>
>> put.addFamily("COMMAND".getBytes(),
"flag".getBytes(),"true".getBytes());
>>
>> Be
We would like to avoid such interruption. A global hashmap storing such a
setting would be more desirable.
Thanks,
Wei
-
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
From: Vladimir Rodionov
To
Hello, I want to check the status of each coprocessor, in a given table.
Let's say I have 3 CPs and one of them is removed due to some unhandled
exception, so I want to see this status (3 deployed, 2 currently alive).
I found this from
http://blogs.apache.org/hbase/entry/coprocessor_introductio
Hi Gary, thanks!
It seems that the region observer been removed behavior, is per region and
NOT per coprocessor. So do I have to query each region to get the per
region health status? Or, is there a table level API telling me something
like, I have 10 regions and an observer has been removed in 2
Hi Gary, thanks for your clarification and yes, I totally agree with your
statement.
The class is not removed but the CP is kind of removed and not active
after an un-handled exception.
I will take a look at the Jira you mentioned.
Best regards,
Wei
From: Gary Helmling
To: user@hbase.
Roman, thanks for sharing your experience. Is your approach is somewhat
similar to Facebook's image store, Haystack?
I am very interested in knowing your use case, and what you actually mean
by class abstraction, internal write buffer, etc.
Best regards,
Wei
From: Roman Nikitchenko
To:
Hi,
In my preput coprocessor I would like to get the old value of the row been
input. Now I am creating a HTable instance and using the get interface;
function wise it works fine. Given the row is physically in the same
region as the cp, is there any lightweight approach doing that?
Thanks!
anted overhead.
-Anoop-
________
From: Wei Tan [w...@us.ibm.com]
Sent: Wednesday, October 10, 2012 2:05 AM
To: hbase-u...@hadoop.apache.org
Subject: connect to the region from coprocessor
Hi,
In my preput coprocessor I would like to get the old value of the row been
input. Now I am creatin
Hi,
I am monitoring the readRequestsCount shown in the "Requests" column in
the web GUI of a server/region. I observe that, while a put correspond to
ONE write request, a get corresponds to 2 readRequestsCount. Is that true
and is there a reason for that? I got the same number in a table with
I wonder if there is any follow up on this issue, i.e., a put can return a
timestamp of the record? Thanks!
Best Regards,
Wei
From: Wei Tan/Watson/IBM
To: user@hbase.apache.org,
Date: 08/02/2012 12:37 PM
Subject:RE: Retrieve Put timestamp
+1.
So far I think timestamp is
Actually coprocessor can be used to implement MR-like function, while not
using Hadoop framework.
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
Yorktown Heights, NY 10598
w...@us.ibm.com; 914-784-6752
From: Dalia Sobhy
To: "user@hbase.apach
Hi I am using YCSB to measure the performance of some complex Get/Scan,
i.e., with some filters. I found that I got weird high latency from YCSB
client but both HBase server and YCSB client are NOT saturated (in terms
of network, I/O, CPU). So I want to measure the server time a single
Get/Scan
Hmm... I appreciate it if anybody can point me how to measure server side
Get/Scan time... Thanks!
Best Regards,
Wei
From: Wei Tan/Watson/IBM
To: hbase-u...@hadoop.apache.org,
Date: 12/02/2012 12:21 PM
Subject:Meaure server time of Get/Scan - through RPC logging?
Hi I am
Andrew, could you explain more, why doing cross-table operation is an
anti-pattern of using CP?
Durability might be an issue, as far as I understand. Thanks,
Best Regards,
Wei
From: Andrew Purtell
To: "user@hbase.apache.org" ,
Date: 01/12/2013 09:39 PM
Subject:Re: Coprocess
avoid RPC.
Otherwise, if you can tolerate consistency but not latency, you put RPCs
in a queue and process them in the background. By this means you can have
a "global" index with some lag.
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
Yorktown
Hi,
I did a quick lookup and found these two threads related to
FuzzyRowFilter status:
https://issues.apache.org/jira/browse/HBASE-7628
https://issues.apache.org/jira/browse/HBASE-6509
It seems that FuzzyRowFilter will be available on 96 and there is a
plan to port it to 94.5. So that is th
Hi I have a table in cluster 1 with quite lengthy metadata (aka,
descriptor). How can I replicate the data as well as descriptor to another
table?
CopyTable, Export/Import does not handle table descriptor.
Thanks,
Wei
Hi Ted, Thanks for your remind. I made it in two steps:
1. write a java problem to create a table using original table's
descriptor.
2. use ./bin/hbase org.apache.hadoop.hbase.mapreduce.CopyTable to copy the
data
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Res
Hi,
I am writing a maven junit test for a HBase coprocessor. The problem is
that, I want to write a junit test that deploy the cp jar into a cluster,
and test its function. However, test is before install so I cannot get a
cp jar to deploy at that time.
Is this like a chicken-and-egg problem? An
Thanks. I may try this approach later.
Now I am using a remote cluster to test and I have this workaround:
mvn install and skip test
copy the cp to the remote cluster
mvn install with test
I doubt if it is a good approach but it works.
Best Regards,
Wei
From: Adrien Mogenet
To: user@
We need to parse JSON in a coprocessor and if HBase /lib directory
contains any json processing util, we can avoid introducing additional
jars.
Thanks!
Best Regards,
Wei
Is your CheckAndPut involving a local or remote READ? Due to the nature of
LSM, read is much slower compared to a write...
Best Regards,
Wei
From: Prakash Kadel
To: "user@hbase.apache.org" ,
Date: 02/17/2013 07:49 PM
Subject:coprocessor enabled put very slow, help please~~~
n a lot of cases, RPC may NOT be the bottle neck. Remember a "local"
put also involves RPC -- during WAL to HDFS.
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
Yorktown Heights, NY 10598
w...@us.ibm.com; 914-945-4386
From: Prakash Kadel
or data processing can be seen as
>>> "unnecessary overhead".
>>>
>>> Thanks
>>>
>>> yong
>>> On Mon, Feb 18, 2013 at 10:35 AM, Michael Segel
>>> wrote:
>>>> Why?
>>>>
&g
We have a similar requirement and here is the solution in our mind:
add a coprocessor, in prePut() get the current ms and set it to put ---
the current implementation get the current ms and set it in put()
return the ms generated to prePut() to client. For now put() does not
return any value. we
+1.
So far I think timestamp is very useful. I would imagine if we can
configure the return, say in pre/post put, it would be even nicer.
Thanks,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
19 Skyline Dr, Hawthorne, NY 10532
w...@us.ibm.com; 914-784-6752
From
.
Thanks,
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
19 Skyline Dr, Hawthorne, NY 10532
w...@us.ibm.com; 914-784-6752
From: "Amlan Roy"
To: ,
Date: 08/06/2012 09:05 AM
Subject:RE: HBase MapReduce - Using mutiple tables as so
oposed by Prof. Eric Brewer...
http://en.wikipedia.org/wiki/Eric_Brewer_%28scientist%29
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
19 Skyline Dr, Hawthorne, NY 10532
w...@us.ibm.com; 914-784-6752
From: Lin Ma
To: user@hbase.apache.org,
Date:
for the chained put (seems to be an index put) to be completed -- this is
causing the timeout.
Best Regards,
Wei
Wei Tan
Research Staff Member
IBM T. J. Watson Research Center
19 Skyline Dr, Hawthorne, NY 10532
w...@us.ibm.com; 914-784-6752
From: Henry JunYoung KIM
To: user
Hi, I have a HBase table where each row has ~1000k columns, ~2K each. My
table scan pattern is to use a row key filter but I need to fetch the
whole row (~1000 k) columns back.
Shall I set HFile block size to be larger than the default 64K?
Thanks,
Wei
-
Wei Tan
To be more clear, each KV (cell) is a couple of KB but each row is a
couple of MB. If I need to search through row key, but always fetch rows
as a whole, shall I use a block size larger than the default 64KB?
Thanks,
Wei
-
Wei Tan, PhD
Research Staff Member
IBM
criteria.
Best regards,
Wei
-
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
From: lars hofhansl
To: "user@hbase.apache.org" ,
Date: 01/29/2014 03:49 PM
Subject:Re: larger H
Thanks for the help from you all.
Best regards,
Wei
---------
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
From: Ted Yu
To: "user@hbase.apache.org" ,
Date: 01/29/2014 04:37 PM
Subject:
I am thinking of storing medium sized objects (~1M) using HBase. The
advantage of using HBase rather than HBase (storing pointers) + HDFS, in
my mind, is:
data locality. When I want to run analytics, I will access these objects
using HBase scan, and HBase stores KVs in a sequential manner. If I
Image :)
Best regards,
Wei
-
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
From: Vladimir Rodionov
To: "user@hbase.apache.org" ,
Date: 02/27/2014 01:22 AM
Subject:RE: I
-
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
,
Wei
-----
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
ese errors on this page seem to be for
"does not work at all" conditions... not a "fails every randomly long
amount of time"
3) we don't have this "problematic combination of components" listed...
but again - this is a work / no work dichotomy...
Thanks,
W
!
Best regards,
Wei
---------
Wei Tan, PhD
Research Staff Member
IBM T. J. Watson Research Center
http://researcher.ibm.com/person/us-wtan
From: Zesheng Wu
To: user@hbase.apache.org,
Date: 03/13/2014 09:33 PM
Subject:Re: Occasional GSSException that brings down region server
Thank you al
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