Examples with NoConnectionsAvailableException org.scale7.cassandra.pelops.exceptions.NoConnectionsAvailableException used on opensource projects

Example 1 with NoConnectionsAvailableException

use of org.scale7.cassandra.pelops.exceptions.NoConnectionsAvailableException in project scale7-pelops by s7.

the class CommonsBackedPool method getConnectionExcept.

@Override
public IPooledConnection getConnectionExcept(Set<String> avoidNodes) throws NoConnectionsAvailableException {
    PooledNode node = null;
    IPooledConnection connection = null;
    long timeout = -1;
    while (connection == null) {
        if (timeout == -1) {
            // first run through calc the timeout for the next loop
            // (this makes debugging easier)
            int maxWait = getPolicy().getMaxWaitForConnection();
            timeout = maxWait > 0 ? System.currentTimeMillis() + maxWait : Long.MAX_VALUE;
        } else if (timeout < System.currentTimeMillis()) {
            logger.debug("Max wait time for connection exceeded");
            break;
        }
        node = nodeSelectionStrategy.select(this, nodes.keySet(), avoidNodes);
        // if the strategy was unable to choose a node (all suspended?) then sleep for a bit and loop
        if (node == null) {
            logger.debug("The node selection strategy was unable to choose a node, sleeping before trying again...");
            try {
                Thread.sleep(DEFAULT_WAIT_PERIOD);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
            continue;
        }
        try {
            logger.debug("Attempting to borrow free connection for node '{}'", node.getAddress());
            // note that if no connections are currently available for this node then the pool will sleep for
            // DEFAULT_WAIT_PERIOD milliseconds
            connection = pool.borrowObject(node.getAddress());
        } catch (IllegalStateException e) {
            throw new PelopsException("The pool has been shutdown", e);
        } catch (Exception e) {
            if (e instanceof NoSuchElementException) {
                logger.debug("No free connections available for node '{}'.  Trying another node...", node.getAddress());
            } else if (e instanceof TTransportException) {
                logger.warn(String.format("A TTransportException was thrown while attempting to create a connection to '%s'.  " + "This node will be suspended for %sms.  Trying another node...", node.getAddress(), this.policy.getNodeDownSuspensionMillis()));
                node.suspendForMillis(this.policy.getNodeDownSuspensionMillis());
            } else
                logger.warn(String.format("An exception was thrown while attempting to create a connection to '%s'.  " + "Trying another node...", node.getAddress()), e);
            // try and avoid this node on the next trip through the loop
            if (avoidNodes == null)
                avoidNodes = new HashSet<String>(10);
            avoidNodes.add(node.getAddress());
        }
    }
    if (node == null) {
        logger.error("Failed to get a connection within the configured wait time because there are no available nodes. " + "This possibly indicates that either the suspension strategy is too aggressive or that your " + "cluster is in a bad way.");
        throw new NoConnectionsAvailableException("Failed to get a connection within the configured max wait time.");
    }
    if (connection == null) {
        logger.error("Failed to get a connection within the maximum allowed wait time.  " + "Try increasing the either the number of allowed connections or the max wait time.");
        throw new NoConnectionsAvailableException("Failed to get a connection within the configured max wait time.");
    }
    logger.debug("Borrowing connection '{}'", connection);
    statistics.connectionsActive.incrementAndGet();
    reportConnectionBorrowed(connection.getNode().getAddress());
    return connection;
}

Example 2 with NoConnectionsAvailableException

use of org.scale7.cassandra.pelops.exceptions.NoConnectionsAvailableException in project scale7-pelops by s7.

the class CommonsBackedPoolIntegrationTest method testsScheduledTaskNodeSuspension.

/**
 * Test that when a node is suspended all it's connections are terminated and that when it comes good it starts
 * returning connections again.
 */
@Test
public void testsScheduledTaskNodeSuspension() throws Exception {
    CommonsBackedPool.Policy config = new CommonsBackedPool.Policy();
    // disable the background thread
    config.setTimeBetweenScheduledMaintenanceTaskRunsMillis(-1);
    config.setMaxActivePerNode(1);
    final AtomicBoolean suspended = new AtomicBoolean(true);
    CommonsBackedPool pool = new CommonsBackedPool(AbstractIntegrationTest.cluster, AbstractIntegrationTest.KEYSPACE, config, new OperandPolicy(), new LeastLoadedNodeSelectionStrategy(), new CommonsBackedPool.INodeSuspensionStrategy() {

        @Override
        public boolean evaluate(CommonsBackedPool pool, PooledNode node) {
            if (suspended.get()) {
                // first run through we want to suspend the node
                suspended.set(false);
                node.setSuspensionState(new CommonsBackedPool.INodeSuspensionState() {

                    @Override
                    public boolean isSuspended() {
                        return true;
                    }
                });
                return true;
            } else {
                // second run through we want the node active
                node.setSuspensionState(new CommonsBackedPool.INodeSuspensionState() {

                    @Override
                    public boolean isSuspended() {
                        return false;
                    }
                });
                return false;
            }
        }
    }, new NoOpConnectionValidator());
    try {
        // node not yet suspended
        IThriftPool.IPooledConnection connection = pool.getConnection();
        connection.release();
        // suspend the node
        pool.runMaintenanceTasks();
        try {
            pool.getConnection();
            fail("No nodes should be available");
        } catch (NoConnectionsAvailableException e) {
        // expected
        }
        // activate the node
        pool.runMaintenanceTasks();
        // node is now active
        connection = pool.getConnection();
        connection.release();
    } finally {
        pool.shutdown();
    }
}

Example 3 with NoConnectionsAvailableException

use of org.scale7.cassandra.pelops.exceptions.NoConnectionsAvailableException in project scale7-pelops by s7.

the class DebuggingPool method getConnection.

@Override
public IPooledConnection getConnection() throws NoConnectionsAvailableException {
    Cluster.Node[] nodes = cluster.getNodes();
    int index = nodes.length == 1 ? 0 : random.nextInt(nodes.length);
    logger.debug("Using node '{}'", nodes[index]);
    if (connection != null && connection.isOpen())
        return connection;
    try {
        connection = new PooledConnection(nodes[index], keyspace);
        connection.open();
    } catch (Exception e) {
        throw new NoConnectionsAvailableException();
    }
    return connection;
}