Connection Pool Shutdown Issue

[dhaval24]

Expected behavior

Application should shutdown gracefully when /shutdown endpoint is hit in Spring / SpringBoot Apps.

Actual behavior

When shutting down SpringBoot Application via /shutdown endpoint, I see the following error and application exists with exit code 1

AI: ERROR 28-08-2018 19:18:29.785+0000, 60(ActiveTransmissionNetworkOutput_1-0): Failed to send, unexpected exception.
Stack Trace:
java.lang.IllegalStateException: Connection pool shut down
        at com.microsoft.applicationinsights.core.dependencies.http.util.Asserts.check(Asserts.java:34)
        at com.microsoft.applicationinsights.core.dependencies.http.pool.AbstractConnPool.lease(AbstractConnPool.java:189)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.conn.PoolingHttpClientConnectionManager.requestConnection(PoolingHttpClientConnectionManager.java:257)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.execchain.MainClientExec.execute(MainClientExec.java:176)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:185)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.execchain.RedirectExec.execute(RedirectExec.java:111)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:108)
        at com.microsoft.applicationinsights.core.dependencies.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
        at com.microsoft.applicationinsights.internal.channel.common.ApacheSender43.sendPostRequest(ApacheSender43.java:75)
        at com.microsoft.applicationinsights.internal.channel.common.TransmissionNetworkOutput.send(TransmissionNetworkOutput.java:185)
        at com.microsoft.applicationinsights.internal.channel.common.ActiveTransmissionNetworkOutput$1.run(ActiveTransmissionNetworkOutput.java:79)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

To Reproduce

1. Create sample springboot app with a rest controller.
2. Use ApplicationInsights Springboot starter to instrument the app.
3. Add following properties to application.properties file:
   endpoints.shutdown.enabled=true
   management.security.enabled=false
4. start the application with mvn spring-boot:run
5. send post request to /shutdown endpoint.

[dhaval24]

This is actually a open ended question!

[littleaj]

I think I found a solution. Creating a PR.
Islandora/documentation#689