How many concurrent connections can be made, will purely depend on number of CPUs (cores) you have available on the database server.
Well, certainly 1 would be the way to go to build an multi-tenant application, but, it strongly depends on your application specific requirements and how are you distributing the data across databases and how the users are accessing data across the databases.
Yup, I also would like to go with 1, suppose a server with 16 core, 32GB memory, SSD box, how many connections could it handle roughly, e.g. O(100) or O(1000) or O(5000)?
Well, as its been said already, you can typically have 16 concurrent connections at a time and more if the CPUs are hyper-threading enabled. All that said, how many requests your database can serve will depend on the fact that, how long each connection is expected to spend on the database. This means, there must an appropriate benchmarking process in place. If you really see a connection/query spending few milli-seconds on the database with some aggressive connection pooling mechanism, then you can get more number of requests served in less time. Generally, it is possible that, 1000s of requests can be served and those being concurrent will be far from real with kind of hardware capacity you have. So, the solution would be to have appropriate tuning and benchmarking process in place.
Regards,
Venkata B N
Fujitsu, Australia
On August 1, 2016 at 10:30:48 PM, Venkata Balaji N (nag1010@gmail.com) wrote:
We are trying build a multi tenant application and are debating which approach we should take: (also my understanding is based on that pgbouncer connection pool doesn’t work across different user/database pair):
1. For each tenant, we create a dedicated database and a dedicated user. This option gives best isolation. However, connection pooling won’t work pgbouncer.
Not sure what you meant by saying connection pooling (pgBouncer) does not work ? This is the general approach for building a multi-tenant application.
2. We put all tenants in a single database, and just use one user. I learned that pgbackup will be probamatic when there are > 30 schemas in a database, so we probably can’t create dedicate schema for each tenant.
We are more inclined to choose 1, but don't know how many concurrent connections Postgres can handle for OLTP workload in a 32GB memory, SSD box. Also we would like hear from someone with more postgres experience about the best practice for building multi-tenant application. Again, i am not sure what you meant by saying pgbackup will not work where there are more than 30 schemas ?
Which version of PostgreSQL are you using ?
How many concurrent connections can be made, will purely depend on number of CPUs (cores) you have available on the database server.
Well, certainly 1 would be the way to go to build an multi-tenant application, but, it strongly depends on your application specific requirements and how are you distributing the data across databases and how the users are accessing data across the databases.
