fix: add support for idle connection monitoring (opt-in for now) #1171
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,8 @@ | ||
| { | ||
| "id": "386353e6-e3cc-4561-bfd6-9763d3ac033b", | ||
| "type": "bugfix", | ||
| "description": "Add support for connection idle monitoring for OkHttp via the engine config parameter `connectionIdlePollingInterval`. Monitoring is disabled by default to match previous behavior. This monitoring will switch to enabled by default in an upcoming minor version release.", | ||
| "issues": [ | ||
| "awslabs/aws-sdk-kotlin#1214" | ||
| ] | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,120 @@ | ||
| /* | ||
| * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. | ||
| * SPDX-License-Identifier: Apache-2.0 | ||
| */ | ||
| package aws.smithy.kotlin.runtime.http.engine.okhttp | ||
|
|
||
| import aws.smithy.kotlin.runtime.telemetry.logging.logger | ||
| import kotlinx.coroutines.CoroutineName | ||
| import kotlinx.coroutines.CoroutineScope | ||
| import kotlinx.coroutines.Dispatchers | ||
| import kotlinx.coroutines.Job | ||
| import kotlinx.coroutines.cancelAndJoin | ||
| import kotlinx.coroutines.isActive | ||
| import kotlinx.coroutines.launch | ||
| import kotlinx.coroutines.runBlocking | ||
| import okhttp3.Call | ||
| import okhttp3.Connection | ||
| import okhttp3.ConnectionListener | ||
| import okhttp3.ExperimentalOkHttpApi | ||
| import okhttp3.internal.closeQuietly | ||
| import okio.EOFException | ||
| import okio.buffer | ||
| import okio.source | ||
| import java.net.SocketException | ||
| import java.net.SocketTimeoutException | ||
| import java.util.concurrent.ConcurrentHashMap | ||
| import kotlin.coroutines.coroutineContext | ||
| import kotlin.time.Duration | ||
| import kotlin.time.measureTime | ||
|
|
||
| @OptIn(ExperimentalOkHttpApi::class) | ||
| internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionListener() { | ||
| private val monitors = ConcurrentHashMap<Connection, Job>() | ||
|
|
||
| private fun Call.callContext() = | ||
| request() | ||
| .tag(SdkRequestTag::class.java) | ||
| ?.callContext | ||
| ?: Dispatchers.IO | ||
|
|
||
| override fun connectionAcquired(connection: Connection, call: Call) { | ||
| // Non-locking map access is okay here because this code will only execute synchronously as part of a | ||
| // `connectionAcquired` event and will be complete before any future `connectionReleased` event could fire for | ||
| // the same connection. | ||
| monitors.remove(connection)?.let { monitor -> | ||
| val context = call.callContext() | ||
| val logger = context.logger<ConnectionIdleMonitor>() | ||
| logger.trace { "Cancel monitoring for $connection" } | ||
|
|
||
| // Use `runBlocking` because this _must_ finish before OkHttp goes to use the connection | ||
| val cancelTime = measureTime { | ||
| runBlocking(context) { monitor.cancelAndJoin() } | ||
| } | ||
|
|
||
| logger.trace { "Monitoring canceled for $connection in $cancelTime" } | ||
| } | ||
| } | ||
|
|
||
| override fun connectionReleased(connection: Connection, call: Call) { | ||
| val connId = System.identityHashCode(connection) | ||
| val context = call.callContext() | ||
| val scope = CoroutineScope(context) | ||
| val monitor = scope.launch(CoroutineName("okhttp-conn-monitor-for-$connId")) { | ||
| doMonitor(connection) | ||
| } | ||
| context.logger<ConnectionIdleMonitor>().trace { "Launched coroutine $monitor to monitor $connection" } | ||
|
|
||
| // Non-locking map access is okay here because this code will only execute synchronously as part of a | ||
| // `connectionReleased` event and will be complete before any future `connectionAcquired` event could fire for | ||
| // the same connection. | ||
| monitors[connection] = monitor | ||
| } | ||
|
|
||
| private suspend fun doMonitor(conn: Connection) { | ||
| val logger = coroutineContext.logger<ConnectionIdleMonitor>() | ||
|
|
||
| val socket = conn.socket() | ||
| val source = try { | ||
| socket.source() | ||
| } catch (_: SocketException) { | ||
| logger.trace { "Socket for $conn closed before monitoring started. Skipping polling loop." } | ||
| return | ||
| }.buffer().peek() | ||
|
|
||
| logger.trace { "Commence socket monitoring for $conn" } | ||
| var resetTimeout = true | ||
| val oldTimeout = socket.soTimeout | ||
|
|
||
| try { | ||
| socket.soTimeout = pollInterval.inWholeMilliseconds.toInt() | ||
|
|
||
| while (coroutineContext.isActive) { | ||
| try { | ||
| logger.trace { "Polling socket for $conn" } | ||
| source.readByte() // Blocking read; will take up to `pollInterval` time to complete | ||
| } catch (_: SocketTimeoutException) { | ||
| logger.trace { "Socket still alive for $conn" } | ||
| } catch (_: EOFException) { | ||
| logger.trace { "Socket closed remotely for $conn" } | ||
| socket.closeQuietly() | ||
| resetTimeout = false | ||
| return | ||
| } | ||
| } | ||
|
|
||
| logger.trace { "Monitoring coroutine has been cancelled. Ending polling loop." } | ||
| } catch (e: Throwable) { | ||
| logger.warn(e) { "Failed to poll $conn. Ending polling loop. Connection may be unstable now." } | ||
| } finally { | ||
| if (resetTimeout) { | ||
| logger.trace { "Attempting to reset soTimeout..." } | ||
| try { | ||
| conn.socket().soTimeout = oldTimeout | ||
|
Comment on lines
+110
to
+113
There was a problem hiding this comment. question: Is it possible for a monitored connection to be pulled and used by OkHttp before we reset the There was a problem hiding this comment. Sort of. We start monitoring when a connection is released after a call and we cancel monitoring when a connection is acquired in preparation for a call. At the point we get the There was a problem hiding this comment. Do we have measurements for how long those health checks last and how long we take to reset the There was a problem hiding this comment. Nvm this comment, I was just misunderstanding something |
||
| } catch (e: Throwable) { | ||
| logger.warn(e) { "Failed to reset socket timeout on $conn. Connection may be unstable now." } | ||
| } | ||
| } | ||
| } | ||
| } | ||
| } | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -9,6 +9,7 @@ import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineConfig | |
| import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineConfigImpl | ||
| import aws.smithy.kotlin.runtime.telemetry.Global | ||
| import aws.smithy.kotlin.runtime.telemetry.TelemetryProvider | ||
| import kotlin.time.Duration | ||
|
|
||
| /** | ||
| * The configuration parameters for an OkHttp HTTP client engine. | ||
|
|
@@ -28,6 +29,22 @@ public class OkHttpEngineConfig private constructor(builder: Builder) : HttpClie | |
| public val Default: OkHttpEngineConfig = OkHttpEngineConfig(Builder()) | ||
| } | ||
|
|
||
| /** | ||
| * The interval in which to poll idle connections for remote closure or `null` to disable monitoring of idle | ||
| * connections. The default value is `null`. | ||
| * | ||
| * When this value is non-`null`, polling is enabled on connections which are released from an engine call and | ||
| * enter the connection pool. Polling consists of a loop that performs blocking reads with the socket timeout | ||
| * set to [connectionIdlePollingInterval]. Polling is cancelled for a connection when the engine acquires it | ||
| * from the pool or when the connection is evicted from the pool and closed. Because the polling loop uses | ||
| * blocking reads, an engine call to acquire or close a connection may be delayed by as much as | ||
| * [connectionIdlePollingInterval]. | ||
| * | ||
| * When this value is `null`, polling is disabled. Idle connections in the pool which are closed remotely may | ||
| * encounter errors when they are acquired for a subsequent call. | ||
| */ | ||
| public val connectionIdlePollingInterval: Duration? = builder.connectionIdlePollingInterval | ||
|
|
||
| /** | ||
| * The maximum number of requests to execute concurrently for a single host. | ||
| */ | ||
|
|
@@ -37,6 +54,7 @@ public class OkHttpEngineConfig private constructor(builder: Builder) : HttpClie | |
| super.toBuilderApplicator()() | ||
|
|
||
| if (this is Builder) { | ||
| connectionIdlePollingInterval = [email protected] | ||
| maxConcurrencyPerHost = [email protected] | ||
| } | ||
| } | ||
|
|
@@ -45,6 +63,22 @@ public class OkHttpEngineConfig private constructor(builder: Builder) : HttpClie | |
| * A builder for [OkHttpEngineConfig] | ||
| */ | ||
| public class Builder : BuilderImpl() { | ||
| /** | ||
| * The interval in which to poll idle connections for remote closure or `null` to disable monitoring of idle | ||
| * connections. The default value is `null`. | ||
| * | ||
| * When this value is non-`null`, polling is enabled on connections which are released from an engine call and | ||
| * enter the connection pool. Polling consists of a loop that performs blocking reads with the socket timeout | ||
| * set to [connectionIdlePollingInterval]. Polling is cancelled for a connection when the engine acquires it | ||
| * from the pool or when the connection is evicted from the pool and closed. Because the polling loop uses | ||
| * blocking reads, an engine call to acquire or close a connection may be delayed by as much as | ||
| * [connectionIdlePollingInterval]. | ||
| * | ||
| * When this value is `null`, polling is disabled. Idle connections in the pool which are closed remotely may | ||
| * encounter errors when they are acquired for a subsequent call. | ||
| */ | ||
| public var connectionIdlePollingInterval: Duration? = null | ||
|
|
||
| /** | ||
| * The maximum number of requests to execute concurrently for a single host. Defaults to [maxConcurrency]. | ||
| */ | ||
|
|
||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,21 @@ | ||
| /* | ||
| * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. | ||
| * SPDX-License-Identifier: Apache-2.0 | ||
| */ | ||
| package aws.smithy.kotlin.runtime.http.test.suite | ||
|
|
||
| import io.ktor.server.application.Application | ||
| import io.ktor.server.response.respondText | ||
| import io.ktor.server.routing.post | ||
| import io.ktor.server.routing.route | ||
| import io.ktor.server.routing.routing | ||
|
|
||
| internal fun Application.connectionTests() { | ||
| routing { | ||
| route("connectionDrop") { | ||
| post { | ||
| call.respondText("Bar") | ||
| } | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Why is measuring the cancel time important here?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The time spent waiting to cancel is blocking and delays the usage of the connection. Measuring that time and emitting it in a subsequent log message can help users tune their polling interval.