[jira] [Created] (HBASE-18872) Backup scaling for multiple table and millions of row

["Vishal Khandelwal (JIRA)" <ji...@apache.org>]

Vishal Khandelwal created HBASE-18872:
-----------------------------------------

             Summary: Backup scaling for multiple table and millions of row
                 Key: HBASE-18872
                 URL: https://issues.apache.org/jira/browse/HBASE-18872
             Project: HBase
          Issue Type: Improvement
            Reporter: Vishal Khandelwal


I did a simple experiment of loading ~200 million rows on a table 1 and nothing in a table 2. This test was done on a local cluster ~ approx 3-4 containers were running in parallel. The focus of the test was not on how much time backup takes but on time spent on the table were no data has been changed.

*Table without Data -->*
Elapsed:	44mins, 52sec
Average Map Time	3sec
Average Shuffle Time	2mins, 35sec
Average Merge Time	0sec
Average Reduce Time	0sec
Map : 2052
Reduce : 1

*Table with Data -->*
Elapsed:	1hrs, 44mins, 10sec
Average Map Time	4sec
Average Shuffle Time	37sec
Average Merge Time	3sec
Average Reduce Time	47sec
Map : 2052
Reduce : 64

All above numbers are a single node cluster so not many mappers run in parallel. but let's extrapolate this to 20 node cluster, with ~100 tables and data size to be backed up various for approx 2000 Wals, let us say each 20 node can process 3 containers i.e 60 wals in parallel. assume 3 sec are spent in each WALs i.e. 6000\ 60 sec -->  100 per table --> 10000 sec for all tables. 
~166 hrs only for filtering.  This does not seem to be scale. (These are just rough numbers from a basic test). As all parsing is O (m (WALS) * n (Tables))

Main intend of this test is to see even the backup of very less churning table might take good amount for just filtering the data. As number of table or data increases, this does not seem scalable 

Even i can see from our current cluster numbers easily close to 100 table, 200 millions rows,  200 -300 GB.

I would suggest that we should have filtering to parse WALs once and to segregate in multiple WALs per table --> hFiles from per table wals. ( just a rough idea).





--
This message was sent by Atlassian JIRA
(v6.4.14#64029)