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https://issues.apache.org/jira/browse/TINKERPOP-2813?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17647720#comment-17647720
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ASF GitHub Bot commented on TINKERPOP-2813:
-------------------------------------------
vkagamlyk commented on code in PR #1882:
URL: https://github.com/apache/tinkerpop/pull/1882#discussion_r1049032960
##########
gremlin-server/src/test/java/org/apache/tinkerpop/gremlin/driver/ClientConnectionIntegrateTest.java:
##########
@@ -21,20 +21,34 @@
import io.netty.handler.codec.CorruptedFrameException;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
+import org.apache.tinkerpop.gremlin.driver.exception.ConnectionException;
+import org.apache.tinkerpop.gremlin.driver.exception.NoHostAvailableException;
import org.apache.tinkerpop.gremlin.driver.ser.Serializers;
import
org.apache.tinkerpop.gremlin.server.AbstractGremlinServerIntegrationTest;
import org.apache.tinkerpop.gremlin.server.TestClientFactory;
import org.apache.tinkerpop.gremlin.util.Log4jRecordingAppender;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
+import org.slf4j.LoggerFactory;
+
+import javax.net.ssl.SSLHandshakeException;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.IntStream;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.number.OrderingComparison.greaterThan;
import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
public class ClientConnectionIntegrateTest extends
AbstractGremlinServerIntegrationTest {
+ private static final org.slf4j.Logger logger =
LoggerFactory.getLogger(ClientConnectionIntegrateTest.class);
Review Comment:
looks redundant, tests use log4j
> Improve driver usability for cases where NoHostAvailableException is
> currently thrown
> -------------------------------------------------------------------------------------
>
> Key: TINKERPOP-2813
> URL: https://issues.apache.org/jira/browse/TINKERPOP-2813
> Project: TinkerPop
> Issue Type: Improvement
> Components: driver
> Affects Versions: 3.5.4
> Reporter: Stephen Mallette
> Assignee: Stephen Mallette
> Priority: Blocker
>
> A {{NoHostAvailableException}} occurs in two cases:
> 1. where the {{Client}} is initialized and a failure occurs on all {{Host}}
> instances configured
> 2. when the {{Client}} attempts to {{chooseConnection()}} to send a request
> and all {{Host}} instances configured are marked unavailable.
> In the first case, you can get a cause for the failure which is helpful, but
> the inadequacy is that you only get the failure of the first {{Host}} to
> cause a problem. The second case is a bit worse because there you get no
> cause in the exception and it's a "fast fail" in that as soon as the request
> is sent there is no pause to see if the {{Host}} comes back online. Moreover,
> a {{Host}} can be marked for failure for the infraction of just a single
> {{Connection}} that may have just encountered a intermittent network issue,
> thus quite quickly killing the entire {{ConnectionPool}} and turning 100s or
> requests per second into 100s of {{NoHostAvailableException}} per second.
> Note that you can also get an infraction for the pool just being overloaded
> with requests which may signal that either the pool or server not being sized
> right for the current workload - in either case, the
> {{NoHostAvailableException}} is a bit of a harsh way to deal with that and in
> any event doesn't quite give the user clues as to how to deal with it.
> All in all, this situation makes {{NoHostAvailableException}} hard to debug.
> This ticket is meant to help smooth some of these problems. Initial thoughts
> for improvements include better logging, ensuring that
> {{NoHostAvailableException}} is not thrown without a cause, preferring more
> specific exceptions in the fist place to {{NoHostAvailableException}},
> getting rid of "fast fails" in favor of longer pauses to see if a host can
> recover and taking a softer stance on when a {{Host}} is actually considered
> "unavailable".
> Expecting to implement this without breaking API changes, though exceptions
> may shift around a bit, but will try to keep those to a minimum.
>
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