Postgres default connection is too high

[shuse2]

Expected behavior

Postgresql default max number of connection is 100, so the SDK should comply with the max number of connection

Actual behavior

Currently max connection is 95 * 3 modules, which is 275.
Therefore, for some case, it will hit the max number of connection.

07:11:24.880Z ERROR lisk-framework: remaining connection slots are reserved for non-replication superuser connections (err.code=53300)
    error: remaining connection slots are reserved for non-replication superuser connections
        at Connection.parseE (/Users/x/xxx/node_modules/pg/lib/connection.js:554:11)
        at Connection.parseMessage (/Users/x/xxx/node_modules/pg/lib/connection.js:379:19)
        at Socket.<anonymous> (/Users/x/xxx/node_modules/pg/lib/connection.js:119:22)
        at Socket.emit (events.js:189:13)
        at Socket.EventEmitter.emit (domain.js:441:20)
        at addChunk (_stream_readable.js:284:12)
        at readableAddChunk (_stream_readable.js:265:11)
        at Socket.Readable.push (_stream_readable.js:220:10)
        at TCP.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)
07:11:24.883Z  INFO lisk-framework: Cleanup controller...
07:11:24.883Z ERROR lisk-framework: Reason: Error: DB Connection Error

Steps to reproduce

Starting the application with default setup

Which version(s) does this affect? (Environment, OS, etc...)

2.0-

[kplusq]

I had a same error in v2.2.0, but there was no trouble in v2.1.0.
There were three instance at v2.1.0. however from v2.2.0, there are four since controller has own connection.
It's just a guess but, is there a possibility that the change might have caused it?
(I tried to do initial DB creation with v2.1.0, then run v2.2.0. In that case, no error occurred.
also I tried to halt http_api module connections, then that worked fine.)

[kplusq]

Sorry, that was my misunderstanding.
I suppose the problem has nothing to do with the number of instance, but a timing of loadBlockChain execution .
In v2.1.0, API module and Network module are loaded before loading Blockchain.
However in v2.2.0, it seems loading those modules are called after loading Blockchain.
so in that case, if max setting is 95, full of connections are used by Chain module.

[nazarhussain]

I agree, that default value was carry forward when every thing was using single db object. Now since load been splitted between modules so default max connection can be reduced.