Thread Pinning With Virtual Threads

[bcluap]

Problem:

There is thread pinning when using the AWS Encryption SDK as it uses an old Apache HTTP client which causes pinning here:

org.apache.http.pool.AbstractConnPool$2.get(AbstractConnPool.java:256) <== monitors:1

The source:
@Override public E get(final long timeout, final TimeUnit timeUnit) throws InterruptedException, ExecutionException, TimeoutException { for (;;) { **synchronized (this) {** try { final E entry = entryRef.get(); if (entry != null) { return entry; } if (done.get()) { throw new ExecutionException(operationAborted()); } final E leasedEntry = getPoolEntryBlocking(route, state, timeout, timeUnit, this); if (validateAfterInactivity > 0) { if (leasedEntry.getUpdated() + validateAfterInactivity <= System.currentTimeMillis()) { if (!validate(leasedEntry)) { leasedEntry.close(); release(leasedEntry, false); continue; } } }

Solution:

The Encryption SDK should allow overirding the HTTP client via an SPI or similar much like many of the other AWS SDK's. Alternatively upgrade to use httpclient5

[texastony]

@bcluap

Thanks for cutting the issue!
The AWS Encryption SDK for Java (ESDK-Java) does, indirectly, allow for overriding the HTTP Client.

The ESDKs are not SDK clients, but they consume SDK Clients.
The consumed SDK client can be customized, otherwise a default one is created.

I authored a PR with an Example to demonstrate customizing the SDK Client.

I used the default ApachHTTP client,
as I did not want to bring in an additional dependency to use the CRT Client,
so the demonstration does not really address your concern.

If the KMS Client object, from the AWS SDK for Java V2,
does not allow you to use an HTTP Client that avoids thread pinning,
we would need to bring this up with @aws/aws-sdk-java-team .