[DE-120] Bugfix swallowing connection exceptions (#420)

* keep track of previous exceptions in HostHandler

* fixed IOException handling in HTTP protocol

* SSL test

Author: rashtao

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>com.arangodb</groupId>
     <artifactId>arangodb-java-driver</artifactId>
-    <version>6.14.0</version>
+    <version>6.15.0-SNAPSHOT</version>
     <inceptionYear>2016</inceptionYear>
     <packaging>jar</packaging>
 

src/main/java/com/arangodb/ArangoDBException.java

@@ -56,6 +56,12 @@ public ArangoDBException(final Throwable cause) {
         this.responseCode = null;
     }
 
+    public ArangoDBException(final String message, final Throwable cause) {
+        super(message, cause);
+        this.entity = null;
+        this.responseCode = null;
+    }
+
     /**
      * @return ArangoDB error message
      */

src/main/java/com/arangodb/ArangoDBMultipleException.java

@@ -0,0 +1,44 @@
+package com.arangodb;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.StringJoiner;
+
+public class ArangoDBMultipleException extends RuntimeException {
+
+    private final List<Throwable> exceptions;
+
+    public ArangoDBMultipleException(List<Throwable> exceptions) {
+        super();
+        this.exceptions = exceptions;
+    }
+
+    public List<Throwable> getExceptions() {
+        return exceptions;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ArangoDBMultipleException that = (ArangoDBMultipleException) o;
+        return Objects.equals(exceptions, that.exceptions);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(exceptions);
+    }
+
+    @Override
+    public String toString() {
+        StringJoiner joiner = new StringJoiner("\n\t", "ArangoDBMultipleException{\n\t", "\n}");
+        for (Throwable t : exceptions) {
+            StringJoiner tJoiner = new StringJoiner("\n\t\t", "\n\t\t", "");
+            for (StackTraceElement stackTraceElement : t.getStackTrace())
+                tJoiner.add("at " + stackTraceElement);
+            joiner.add(t + tJoiner.toString());
+        }
+        return joiner.toString();
+    }
+}

src/main/java/com/arangodb/async/internal/velocystream/VstCommunicationAsync.java

@@ -85,7 +85,7 @@ protected CompletableFuture<Response> execute(final Request request, final VstCo
                         final String location = e.getLocation();
                         final HostDescription redirectHost = HostUtils.createFromLocation(location);
                         hostHandler.closeCurrentOnError();
-                        hostHandler.fail();
+                        hostHandler.fail(e);
                         execute(request, new HostHandle().setHost(redirectHost), attemptCount + 1)
                                 .whenComplete((v, err) -> {
                                     if (v != null) {

src/main/java/com/arangodb/internal/http/HttpCommunication.java

@@ -32,7 +32,6 @@
 
 import java.io.Closeable;
 import java.io.IOException;
-import java.net.SocketException;
 
 /**
  * @author Mark Vollmary
@@ -71,11 +70,11 @@ public void close() throws IOException {
         hostHandler.close();
     }
 
-    public Response execute(final Request request, final HostHandle hostHandle) throws ArangoDBException, IOException {
+    public Response execute(final Request request, final HostHandle hostHandle) throws ArangoDBException {
         return execute(request, hostHandle, 0);
     }
 
-    private Response execute(final Request request, final HostHandle hostHandle, final int attemptCount) throws ArangoDBException, IOException {
+    private Response execute(final Request request, final HostHandle hostHandle, final int attemptCount) throws ArangoDBException {
         final AccessType accessType = RequestUtils.determineAccessType(request);
         Host host = hostHandler.get(hostHandle, accessType);
         try {
@@ -86,19 +85,20 @@ private Response execute(final Request request, final HostHandle hostHandle, fin
                     hostHandler.success();
                     hostHandler.confirm();
                     return response;
-                } catch (final SocketException se) {
-                    hostHandler.fail();
+                } catch (final IOException e) {
+                    hostHandler.fail(e);
                     if (hostHandle != null && hostHandle.getHost() != null) {
                         hostHandle.setHost(null);
                     }
                     final Host failedHost = host;
                     host = hostHandler.get(hostHandle, accessType);
                     if (host != null) {
-                        LOGGER.warn(String.format("Could not connect to %s", failedHost.getDescription()), se);
+                        LOGGER.warn(String.format("Could not connect to %s", failedHost.getDescription()), e);
                         LOGGER.warn(String.format("Could not connect to %s. Try connecting to %s",
                                 failedHost.getDescription(), host.getDescription()));
                     } else {
-                        throw se;
+                        LOGGER.error(e.getMessage(), e);
+                        throw new ArangoDBException(e);
                     }
                 }
             }
@@ -107,7 +107,7 @@ private Response execute(final Request request, final HostHandle hostHandle, fin
                 final String location = ((ArangoDBRedirectException) e).getLocation();
                 final HostDescription redirectHost = HostUtils.createFromLocation(location);
                 hostHandler.closeCurrentOnError();
-                hostHandler.fail();
+                hostHandler.fail(e);
                 return execute(request, new HostHandle().setHost(redirectHost), attemptCount + 1);
             } else {
                 throw e;

src/main/java/com/arangodb/internal/http/HttpProtocol.java

@@ -42,11 +42,7 @@ public HttpProtocol(final HttpCommunication httpCommunitaction) {
 
     @Override
     public Response execute(final Request request, final HostHandle hostHandle) throws ArangoDBException {
-        try {
-            return httpCommunitaction.execute(request, hostHandle);
-        } catch (final IOException e) {
-            throw new ArangoDBException(e);
-        }
+        return httpCommunitaction.execute(request, hostHandle);
     }
 
     @Override

src/main/java/com/arangodb/internal/net/DirtyReadHostHandler.java

@@ -56,8 +56,8 @@ public void success() {
     }
 
     @Override
-    public void fail() {
-        determineHostHandler().fail();
+    public void fail(Exception exception) {
+        determineHostHandler().fail(exception);
     }
 
     @Override

src/main/java/com/arangodb/internal/net/FallbackHostHandler.java

@@ -21,7 +21,9 @@
 package com.arangodb.internal.net;
 
 import com.arangodb.ArangoDBException;
+import com.arangodb.ArangoDBMultipleException;
 
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -33,12 +35,14 @@ public class FallbackHostHandler implements HostHandler {
     private Host current;
     private Host lastSuccess;
     private int iterations;
+    private final List<Throwable> lastFailExceptions;
     private boolean firstOpened;
     private HostSet hosts;
 
     public FallbackHostHandler(final HostResolver resolver) {
         this.resolver = resolver;
-        iterations = 0;
+        lastFailExceptions = new ArrayList<>();
+        reset();
         hosts = resolver.resolve(true, false);
         current = lastSuccess = hosts.getHostsList().get(0);
         firstOpened = true;
@@ -49,19 +53,21 @@ public Host get(final HostHandle hostHandle, AccessType accessType) {
         if (current != lastSuccess || iterations < 3) {
             return current;
         } else {
+            ArangoDBException e = new ArangoDBException("Cannot contact any host!",
+                    new ArangoDBMultipleException(new ArrayList<>(lastFailExceptions)));
             reset();
-            throw new ArangoDBException("Cannot contact any host!");
+            throw e;
         }
     }
 
     @Override
     public void success() {
         lastSuccess = current;
-        iterations = 0;
+        reset();
     }
 
     @Override
-    public void fail() {
+    public void fail(Exception exception) {
         hosts = resolver.resolve(false, false);
         final List<Host> hostList = hosts.getHostsList();
         final int index = hostList.indexOf(current) + 1;
@@ -70,11 +76,13 @@ public void fail() {
         if (!inBound) {
             iterations++;
         }
+        lastFailExceptions.add(exception);
     }
 
     @Override
     public void reset() {
         iterations = 0;
+        lastFailExceptions.clear();
     }
 
     @Override

src/main/java/com/arangodb/internal/net/HostHandler.java

@@ -31,7 +31,7 @@ public interface HostHandler {
 
     void success();
 
-    void fail();
+    void fail(Exception exception);
 
     void reset();
 

src/main/java/com/arangodb/internal/net/RandomHostHandler.java

@@ -54,8 +54,8 @@ public void success() {
     }
 
     @Override
-    public void fail() {
-        fallback.fail();
+    public void fail(Exception exception) {
+        fallback.fail(exception);
         current = fallback.get(null, null);
     }