Cannot acquire connection on many "refresh"

When i try to refresh my application running on sbt, it seems like the connection pool is not releasing connections.

Here is the error

[debug] com.zaxxer.hikari.pool.HikariPool - Cannot acquire connection from data source
org.postgresql.util.PSQLException: The connection attempt failed.
	at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:292)
	at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
	at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
	at org.postgresql.Driver.makeConnection(Driver.java:454)
	at org.postgresql.Driver.connect(Driver.java:256)
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:117)
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:123)
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:365)
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:194)
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:460)
Caused by: java.net.SocketException: Bad file descriptor (Write failed)
	at java.net.SocketOutputStream.socketWrite0(Native Method)
	at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
	at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
	at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
	at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
	at org.postgresql.core.PGStream.flush(PGStream.java:527)
	at org.postgresql.core.v3.ConnectionFactoryImpl.sendStartupPacket(ConnectionFactoryImpl.java:480)
	at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:138)
	at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
	at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)

The config we use is this :

  profile = "utils.MyPostgresProfile$"
  db {
    url = "jdbc:postgresql://localhost:5432/<dbname>?currentSchema=app&loggerLevel=TRACE&loggerFile=./log_pgsql.log&connectTimeout=3&socketTimeout=5&tcpKeepAlive=true&sslmode=disable&ssl=false&"
    properties.driver = "org.postgresql.Driver"
    user = <myuser>
    password = <mypassword>
    poolName = <mypoolname>
    registerMbeans = false
    connectionTimeout = 10s
    connectionInitSql = "SELECT 1"
    connectionTestQuery = "SELECT 1"
    validationTimeout = 5000
    idleTimeout = 300000
    maxLifetime = 50000
    minimumIdle = 10
    leakDetectionThreshold=2000
    maximumPoolSize = 25
    initializationFailTimeout = 0
  }
}

which is then taken under by Hikari and it looks like this

[warn] com.zaxxer.hikari.HikariConfig - The initializationFailFast propery is deprecated, see initializationFailTimeout
[warn] com.zaxxer.hikari.HikariConfig - app - idleTimeout is close to or more than maxLifetime, disabling it.
[debug] com.zaxxer.hikari.HikariConfig - app - configuration:
[debug] com.zaxxer.hikari.HikariConfig - allowPoolSuspension.............false
[debug] com.zaxxer.hikari.HikariConfig - autoCommit......................true
[debug] com.zaxxer.hikari.HikariConfig - catalog.........................none
[debug] com.zaxxer.hikari.HikariConfig - connectionInitSql..............."SELECT 1"
[debug] com.zaxxer.hikari.HikariConfig - connectionTestQuery............."SELECT 1"
[debug] com.zaxxer.hikari.HikariConfig - connectionTimeout...............10000
[debug] com.zaxxer.hikari.HikariConfig - dataSource......................none
[debug] com.zaxxer.hikari.HikariConfig - dataSourceClassName.............none
[debug] com.zaxxer.hikari.HikariConfig - dataSourceJNDI..................none
[debug] com.zaxxer.hikari.HikariConfig - dataSourceProperties............{password=<masked>, driver=org.postgresql.Driver}
[debug] com.zaxxer.hikari.HikariConfig - driverClassName.................none
[debug] com.zaxxer.hikari.HikariConfig - healthCheckProperties...........{}
[debug] com.zaxxer.hikari.HikariConfig - healthCheckRegistry.............none
[debug] com.zaxxer.hikari.HikariConfig - idleTimeout.....................0
[debug] com.zaxxer.hikari.HikariConfig - initializationFailFast..........false
[debug] com.zaxxer.hikari.HikariConfig - initializationFailTimeout.......-1
[debug] com.zaxxer.hikari.HikariConfig - isolateInternalQueries..........false
[debug] com.zaxxer.hikari.HikariConfig - jdbc4ConnectionTest.............false
[debug] com.zaxxer.hikari.HikariConfig - jdbcUrl.........................jdbc:postgresql://localhost:5432/<mydbname>?currentSchema=app&loggerLevel=TRACE&loggerFile=./log_pgsql.log&connectTimeout=3&socketTimeout=5&tcpKeepAlive=true&sslmode=disable&ssl=false&
[debug] com.zaxxer.hikari.HikariConfig - leakDetectionThreshold..........2000
[debug] com.zaxxer.hikari.HikariConfig - maxLifetime.....................50000
[debug] com.zaxxer.hikari.HikariConfig - maximumPoolSize.................100
[debug] com.zaxxer.hikari.HikariConfig - metricRegistry..................none
[debug] com.zaxxer.hikari.HikariConfig - metricsTrackerFactory...........none
[debug] com.zaxxer.hikari.HikariConfig - minimumIdle.....................20
[debug] com.zaxxer.hikari.HikariConfig - password........................<masked>
[debug] com.zaxxer.hikari.HikariConfig - poolName........................<mypoolname>
[debug] com.zaxxer.hikari.HikariConfig - readOnly........................false
[debug] com.zaxxer.hikari.HikariConfig - registerMbeans..................false
[debug] com.zaxxer.hikari.HikariConfig - scheduledExecutor...............none
[debug] com.zaxxer.hikari.HikariConfig - scheduledExecutorService........internal
[debug] com.zaxxer.hikari.HikariConfig - schema..........................none
[debug] com.zaxxer.hikari.HikariConfig - threadFactory...................internal
[debug] com.zaxxer.hikari.HikariConfig - transactionIsolation............default
[debug] com.zaxxer.hikari.HikariConfig - username........................<myuser>
[debug] com.zaxxer.hikari.HikariConfig - validationTimeout...............5000

And its always, always happening after 5 refresh. No matter what I set in maxConnections, numThreads, etc etc etc.

Any idea ?!

Start by reproducing the failure with the reported sbt refresh workflow and compare the configured pool values with the effective Hikari configuration shown in the logs. Inspect the PostgreSQL connection settings, refresh lifecycle, and pool behavior; done means identifying a reproducible cause for the connection failure after repeated refreshes and documenting the verified resolution.