mirror of https://github.com/waku-org/nwaku.git
48 lines
1.4 KiB
Nim
48 lines
1.4 KiB
Nim
when (NimMajor, NimMinor) < (1, 4):
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{.push raises: [Defect].}
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else:
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{.push raises: [].}
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import
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chronos,
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stew/results
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import
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../../driver,
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../../../common/databases/db_postgres
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## Simple query to validate that the postgres is working and attending requests
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const HealthCheckQuery = "SELECT version();"
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const CheckConnectivityInterval = 30.seconds
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const MaxNumTrials = 20
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const TrialInterval = 1.seconds
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proc checkConnectivity*(connPool: PgAsyncPool,
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onErrAction: OnErrHandler) {.async.} =
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while true:
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(await connPool.exec(HealthCheckQuery)).isOkOr:
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## The connection failed once. Let's try reconnecting for a while.
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## Notice that the 'exec' proc tries to establish a new connection.
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block errorBlock:
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## Force close all the opened connections. No need to close gracefully.
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(await connPool.resetConnPool()).isOkOr:
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onErrAction("checkConnectivity resetConnPool error: " & error)
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var numTrial = 0
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while numTrial < MaxNumTrials:
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let res = await connPool.exec(HealthCheckQuery)
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if res.isOk():
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## Connection resumed. Let's go back to the normal healthcheck.
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break errorBlock
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await sleepAsync(TrialInterval)
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numTrial.inc()
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## The connection couldn't be resumed. Let's inform the upper layers.
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onErrAction("postgres health check error: " & error)
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await sleepAsync(CheckConnectivityInterval)
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