public boolean isActive(MessageContext synMessageContext) 
{
        boolean active = endpointContext.isActive();
        if (!active) {
            long recoverOn = endpointContext.getRecoverOn();
            if (System.currentTimeMillis()  > recoverOn) {
                active = true;
                endpointContext.setActive(true);
                endpointContext.setRecoverOn(0);                       
            }
        }
        if (log.isDebugEnabled()) {
            log.debug("AddressEndpoint with name '" + getName() + "' is in "
                    + (active ? "active" : "inactive") + " state");
        }
        return active;
}

Checks if the endpoint is active (failed or not). If endpoint is in failed state and suspendOnFailDuration has elapsed, it will be set to active.

 public  void onFault(MessageContext synCtx) 
{
        // perform retries here
        // if this endpoint has actually failed, inform the parent.
        setActive(false, synCtx);
        super.onFault(synCtx);
}

 public  void send(MessageContext synCtx) 
{
        boolean traceOn = isTraceOn(synCtx);
        boolean traceOrDebugOn = isTraceOrDebugOn(traceOn);
        if (traceOrDebugOn) {
            traceOrDebug(traceOn, "Start : Address Endpoint");
            if (traceOn && trace.isTraceEnabled()) {
                trace.trace("Message : " + synCtx.getEnvelope());
            }
        }
        boolean isClusteringEnable = false;
        // get Axis2 MessageContext and ConfigurationContext
        org.apache.axis2.context.MessageContext axisMC =
                ((Axis2MessageContext) synCtx).getAxis2MessageContext();
        ConfigurationContext cc = axisMC.getConfigurationContext();
        //The check for clustering environment
        ClusterManager clusterManager = cc.getAxisConfiguration().getClusterManager();
        if (clusterManager != null &&
                clusterManager.getContextManager() != null) {
            isClusteringEnable = true;
        }
        String endPointName = this.getName();
        if (endPointName == null) {
            if (traceOrDebugOn && isClusteringEnable) {
                log.warn(SALoadbalanceEndpoint.WARN_MESSAGE);
            }
            endPointName = SynapseConstants.ANONYMOUS_ENDPOINT;
        }
        if (isClusteringEnable) {
            // if this is a cluster environment , then set configuration context to endpoint context
            if (endpointContext.getConfigurationContext() == null) {
                endpointContext.setConfigurationContext(cc);
                endpointContext.setContextID(endPointName); // The context ID
            }
        }
        EndpointDefinition endpoint = getEndpoint();
        // Setting Required property to collect the End Point statistics
        boolean statisticsEnable
                = (SynapseConstants.STATISTICS_ON == endpoint.getStatisticsState());
        if (statisticsEnable) {
            EndPointStatisticsStack endPointStatisticsStack = null;
            Object statisticsStackObj =
                    synCtx.getProperty(org.apache.synapse.SynapseConstants.ENDPOINT_STATS);
            if (statisticsStackObj == null) {
                endPointStatisticsStack = new EndPointStatisticsStack();
                synCtx.setProperty(org.apache.synapse.SynapseConstants.ENDPOINT_STATS,
                        endPointStatisticsStack);
            } else if (statisticsStackObj instanceof EndPointStatisticsStack) {
                endPointStatisticsStack = (EndPointStatisticsStack) statisticsStackObj;
            }
            if (endPointStatisticsStack != null) {
                boolean isFault = synCtx.getEnvelope().getBody().hasFault();
                endPointStatisticsStack.put(endPointName, System.currentTimeMillis(),
                        !synCtx.isResponse(), statisticsEnable, isFault);
            }
        }
        if (endpoint.getAddress() != null) {
            if (traceOrDebugOn) {
                traceOrDebug(traceOn, "Sending message to endpoint : " +
                        endPointName + " resolves to address = " + endpoint.getAddress());
                traceOrDebug(traceOn, "SOAPAction: " + (synCtx.getSoapAction() != null ?
                        synCtx.getSoapAction() : "null"));
                traceOrDebug(traceOn, "WSA-Action: " + (synCtx.getWSAAction() != null ?
                        synCtx.getWSAAction() : "null"));
                if (traceOn && trace.isTraceEnabled()) {
                    trace.trace("Envelope : \n" + synCtx.getEnvelope());
                }
            }
        }
        // register this as the immediate fault handler for this message.
        synCtx.pushFaultHandler(this);
        // add this as the last endpoint to process this message. it is used by statistics code.
        synCtx.setProperty(SynapseConstants.PROCESSED_ENDPOINT, this);
        synCtx.getEnvironment().send(endpoint, synCtx);
}

Sends the message through this endpoint. This method just handles statistics related functions and gives the message to the Synapse environment to send. It does not add any endpoint specific details to the message context. These details are added only to the cloned message context by the Axis2FlexibleMepClient. So that we can reuse the original message context for resending through different endpoints.

 public synchronized  void setActive(boolean active,
    MessageContext synMessageContext) 
{
        // this is synchronized as recoverOn can be set to unpredictable values if two threads call
        // this method simultaneously.
        if (!active) {
            EndpointDefinition endpoint = getEndpoint();
            if (endpoint.getSuspendOnFailDuration() != -1) {
                // Calculating a new value by adding suspendOnFailDuration to current time.
                // as the endpoint is set as failed
                endpointContext.setRecoverOn(
                        System.currentTimeMillis() + endpoint.getSuspendOnFailDuration());
            } else {
                endpointContext.setRecoverOn(Long.MAX_VALUE);
            }
        }
        this.endpointContext.setActive(active);
}

Sets if endpoint active or not. if endpoint is set as failed (active = false), the recover on time is calculated so that it will be activated after the recover on time.