in src/main/java/org/apache/sling/discovery/base/connectors/ping/TopologyConnectorClient.java [142:341]
void ping(final boolean force) {
if (autoStopped) {
// then we suppress any further pings!
logger.debug("ping: autoStopped=true, hence suppressing any further pings.");
return;
}
if (force) {
backoffPeriodEnd = -1;
} else if (backoffPeriodEnd>0) {
if (System.currentTimeMillis()<backoffPeriodEnd) {
logger.debug("ping: not issueing a heartbeat due to backoff instruction from peer.");
return;
} else {
logger.debug("ping: backoff period ended, issuing another ping now.");
}
}
final String uri = connectorUrl.toString()+"."+clusterViewService.getSlingId()+".json";
if (logger.isDebugEnabled()) {
logger.debug("ping: connectorUrl=" + connectorUrl + ", complete uri=" + uri);
}
final HttpClientContext clientContext = HttpClientContext.create();
final CloseableHttpClient httpClient = createHttpClient();
final HttpPut putRequest = new HttpPut(uri);
// setting the connection timeout (idle connection, configured in seconds)
putRequest.setConfig(RequestConfig.
custom().
setConnectTimeout(1000*config.getSocketConnectTimeout()).
build());
Announcement resultingAnnouncement = null;
try {
String userInfo = connectorUrl.getUserInfo();
if (userInfo != null) {
Credentials c = new UsernamePasswordCredentials(userInfo);
clientContext.getCredentialsProvider().setCredentials(
new AuthScope(putRequest.getURI().getHost(), putRequest
.getURI().getPort()), c);
}
Announcement topologyAnnouncement = new Announcement(
clusterViewService.getSlingId());
topologyAnnouncement.setServerInfo(serverInfo);
final ClusterView clusterView;
try {
clusterView = clusterViewService
.getLocalClusterView();
} catch (UndefinedClusterViewException e) {
// SLING-5030 : then we cannot ping
logger.warn("ping: no clusterView available at the moment, cannot ping others now: "+e);
return;
}
topologyAnnouncement.setLocalCluster(clusterView);
if (force) {
logger.debug("ping: sending a resetBackoff");
topologyAnnouncement.setResetBackoff(true);
}
announcementRegistry.addAllExcept(topologyAnnouncement, clusterView, new AnnouncementFilter() {
public boolean accept(final String receivingSlingId, final Announcement announcement) {
// filter out announcements that are of old cluster instances
// which I dont really have in my cluster view at the moment
final Iterator<InstanceDescription> it =
clusterView.getInstances().iterator();
while(it.hasNext()) {
final InstanceDescription instance = it.next();
if (instance.getSlingId().equals(receivingSlingId)) {
// then I have the receiving instance in my cluster view
// all fine then
return true;
}
}
// looks like I dont have the receiving instance in my cluster view
// then I should also not propagate that announcement anywhere
return false;
}
});
final String p = requestValidator.encodeMessage(topologyAnnouncement.asJSON());
if (logger.isDebugEnabled()) {
logger.debug("ping: topologyAnnouncement json is: " + p);
}
requestValidator.trustMessage(putRequest, p);
if (config.isGzipConnectorRequestsEnabled()) {
// tell the server that the content is gzipped:
putRequest.addHeader("Content-Encoding", "gzip");
// and gzip the body:
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
final GZIPOutputStream gzipOut = new GZIPOutputStream(baos);
gzipOut.write(p.getBytes("UTF-8"));
gzipOut.close();
final byte[] gzippedEncodedJson = baos.toByteArray();
putRequest.setEntity(new ByteArrayEntity(gzippedEncodedJson, ContentType.APPLICATION_JSON));
lastRequestEncoding = "gzip";
} else {
// otherwise plaintext:
final StringEntity plaintext = new StringEntity(p, "UTF-8");
plaintext.setContentType(ContentType.APPLICATION_JSON.getMimeType());
putRequest.setEntity(plaintext);
lastRequestEncoding = "plaintext";
}
// independent of request-gzipping, we do accept the response to be gzipped,
// so indicate this to the server:
putRequest.addHeader("Accept-Encoding", "gzip");
final CloseableHttpResponse response = httpClient.execute(putRequest, clientContext);
if (logger.isDebugEnabled()) {
logger.debug("ping: done. code=" + response.getStatusLine().getStatusCode() + " - "
+ response.getStatusLine().getReasonPhrase());
}
lastStatusCode = response.getStatusLine().getStatusCode();
lastResponseEncoding = null;
if (response.getStatusLine().getStatusCode()==HttpServletResponse.SC_OK) {
final Header contentEncoding = response.getFirstHeader("Content-Encoding");
if (contentEncoding!=null && contentEncoding.getValue()!=null &&
contentEncoding.getValue().contains("gzip")) {
lastResponseEncoding = "gzip";
} else {
lastResponseEncoding = "plaintext";
}
final String responseBody = requestValidator.decodeMessage(putRequest.getURI().getPath(), response); // limiting to 16MB, should be way enough
if (logger.isDebugEnabled()) {
logger.debug("ping: response body=" + responseBody);
}
if (responseBody!=null && responseBody.length()>0) {
Announcement inheritedAnnouncement = Announcement
.fromJSON(responseBody);
final long backoffInterval = inheritedAnnouncement.getBackoffInterval();
if (backoffInterval>0) {
// then reset the backoffPeriodEnd:
/* minus 1 sec to avoid slipping the interval by a few millis */
this.backoffPeriodEnd = System.currentTimeMillis() + (1000 * backoffInterval) - 1000;
logger.debug("ping: servlet instructed to backoff: backoffInterval="+backoffInterval+", resulting in period end of "+new Date(backoffPeriodEnd));
} else {
logger.debug("ping: servlet did not instruct any backoff-ing at this stage");
this.backoffPeriodEnd = -1;
}
if (inheritedAnnouncement.isLoop()) {
if (logger.isDebugEnabled()) {
logger.debug("ping: connector response indicated a loop detected. not registering this announcement from "+
inheritedAnnouncement.getOwnerId());
}
if (inheritedAnnouncement.getOwnerId().equals(clusterViewService.getSlingId())) {
// SLING-3316 : local-loop detected. Check config to see if we should stop this connector
if (config.isAutoStopLocalLoopEnabled()) {
inheritedAnnouncement = null; // results in connected -> false and representsloop -> true
autoStopped = true; // results in isAutoStopped -> true
}
}
} else {
inheritedAnnouncement.setInherited(true);
if (announcementRegistry
.registerAnnouncement(inheritedAnnouncement)==-1) {
if (logger.isDebugEnabled()) {
logger.debug("ping: connector response is from an instance which I already see in my topology"
+ inheritedAnnouncement);
}
statusDetails = "receiving side is seeing me via another path (connector or cluster) already (loop)";
return;
}
}
resultingAnnouncement = inheritedAnnouncement;
statusDetails = null;
} else {
statusDetails = "no response body received";
}
} else {
statusDetails = "got HTTP Status-Code: "+lastStatusCode;
}
// SLING-2882 : reset suppressPingWarnings_ flag in success case
suppressPingWarnings_ = false;
} catch (IOException e) {
// SLING-2882 : set/check the suppressPingWarnings_ flag
if (suppressPingWarnings_) {
if (logger.isDebugEnabled()) {
logger.debug("ping: got IOException: " + e + ", uri=" + uri);
}
} else {
suppressPingWarnings_ = true;
logger.warn("ping: got IOException [suppressing further warns]: " + e + ", uri=" + uri);
}
statusDetails = e.toString();
} catch (JsonException e) {
logger.warn("ping: got JSONException: " + e);
statusDetails = e.toString();
} catch (RuntimeException re) {
logger.warn("ping: got RuntimeException: " + re, re);
statusDetails = re.toString();
} finally {
putRequest.releaseConnection();
lastInheritedAnnouncement = resultingAnnouncement;
lastPingedAt = System.currentTimeMillis();
try {
httpClient.close();
} catch (IOException e) {
logger.error("disconnect: could not close httpClient: "+e, e);
}
}
}