?
Solved

Load balance Three Postgresql database (Primary, Secondery1 and Secondery2) Servers

Posted on 2014-07-24
5
Medium Priority
?
667 Views
Last Modified: 2014-07-27
Hi Experts,

I have somewhat large Postgresql database to manage and it's about 10GB after I made a dump and I believe it will take about 100GB space after it's populated on a hard disk. Currently I have implemented this on a Standby hot replication cluster. Two basic modules are running in this application and some reporting modules are directly connecting to the Secondary node(read only) and still there some SELECT queries coming in to Primary node(read/write) too.

Pgbouncer has implemented on both of these two database servers and currently operates on Transaction mode.  

I get too high I/O rate and Processing rates ( %I/O wait is around 15 ~ 20, Load leverage is around 8 ~ 10) in the peak times. (these two databases are running on SSD with 8 cores of 2.5 Ghz, two Blades, Ubuntu 12.04 server 64bit )

So I'm planning to add third read only server and implement a mechanism to balance the load across these three DB servers. Example, filter all the read requests on secondery1, secondery2  and write requests on the Primary.

Did any one tried this with pgpool-II, or what is your valuable recommendation on such a situation ?

Thanks a lot for your time !
0
Comment
Question by:Shakthi777
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 40

Assisted Solution

by:lcohan
lcohan earned 664 total points
ID: 40218059
"Two basic modules are running in this application and some reporting modules are directly connecting to the Secondary node(read only) and still there some SELECT queries coming in to Primary node(read/write) too. "

In my opinion it would be better to direct the traffic from the application to the desired instance and not from the backend database servers. In other words the app should have 2/3 connection strings (and app pools) to direct the queries against the desired "node" for the desired purpose.
0
 
LVL 32

Accepted Solution

by:
Daniel Wilson earned 1336 total points
ID: 40218399
Another option is pl/Proxy.
https://wiki.postgresql.org/wiki/PL/Proxy

That is the solution Hannu Krosing developed to scale Postgres for Skype.

I haven't yet implemented a cluster in PostgreSQL, but PL/Proxy is the tool I expect to use ... later this year.
0
 

Author Comment

by:Shakthi777
ID: 40219552
I really wanted to thank for all your prompt responses,

#lcohan
This applications has implemented with a single connections string, any good approach on separating those ?

#Daniel Wilson
Partitioning is another option it's seems ?
0
 
LVL 32

Assisted Solution

by:Daniel Wilson
Daniel Wilson earned 1336 total points
ID: 40220328
PL/Proxy involves a partitioning / sharding scheme.  The application knows nothing of the sharding.  It simply talks to the proxy.  The proxy knows which shard to contact .
0
 

Author Closing Comment

by:Shakthi777
ID: 40223501
Thanks for the valuable comments !
0

Featured Post

Veeam Task Manager for Hyper-V

Task Manager for Hyper-V provides critical information that allows you to monitor Hyper-V performance by displaying real-time views of CPU and memory at the individual VM-level, so you can quickly identify which VMs are using host resources.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article shows the steps required to install WordPress on Azure. Web Apps, Mobile Apps, API Apps, or Functions, in Azure all these run in an App Service plan. WordPress is no exception and requires an App Service Plan and Database to install
Your data is at risk. Probably more today that at any other time in history. There are simply more people with more access to the Web with bad intentions.
Learn how to get help with Linux/Unix bash shell commands. Use help to read help documents for built in bash shell commands.: Use man to interface with the online reference manuals for shell commands.: Use man to search man pages for unknown command…
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial
Suggested Courses

764 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question