order
This paper mainly studies nimbus.seeds parameter of storm client
NIMBUS_SEEDS
storm-core-1.1.0-sources.jar!/org/apache/storm/Config.java
/** * The host that the master server is running on, added only for backward compatibility, * the usage deprecated in favor of nimbus.seeds config. */ @Deprecated @isString public static final String NIMBUS_HOST = "nimbus.host"; /** * List of seed nimbus hosts to use for leader nimbus discovery. */ @isStringList public static final String NIMBUS_SEEDS = "nimbus.seeds";
- You can see that the nimbus.host parameter is abolished here, while the nimbus.seeds parameter is mainly used to discover the nimbus leader
StormSubmitter
storm-core-1.1.0-sources.jar!/org/apache/storm/StormSubmitter.java
public static void submitTopologyAs(String name, Map stormConf, StormTopology topology, SubmitOptions opts, ProgressListener progressListener, String asUser) throws AlreadyAliveException, InvalidTopologyException, AuthorizationException, IllegalArgumentException { if(!Utils.isValidConf(stormConf)) { throw new IllegalArgumentException("Storm conf is not valid. Must be json-serializable"); } stormConf = new HashMap(stormConf); stormConf.putAll(Utils.readCommandLineOpts()); Map conf = Utils.readStormConfig(); conf.putAll(stormConf); stormConf.putAll(prepareZookeeperAuthentication(conf)); validateConfs(conf, topology); Map<String,String> passedCreds = new HashMap<>(); if (opts != null) { Credentials tmpCreds = opts.get_creds(); if (tmpCreds != null) { passedCreds = tmpCreds.get_creds(); } } Map<String,String> fullCreds = populateCredentials(conf, passedCreds); if (!fullCreds.isEmpty()) { if (opts == null) { opts = new SubmitOptions(TopologyInitialStatus.ACTIVE); } opts.set_creds(new Credentials(fullCreds)); } try { if (localNimbus!=null) { LOG.info("Submitting topology " + name + " in local mode"); if (opts!=null) { localNimbus.submitTopologyWithOpts(name, stormConf, topology, opts); } else { // this is for backwards compatibility localNimbus.submitTopology(name, stormConf, topology); } LOG.info("Finished submitting topology: " + name); } else { String serConf = JSONValue.toJSONString(stormConf); try (NimbusClient client = NimbusClient.getConfiguredClientAs(conf, asUser)) { if (topologyNameExists(name, client)) { throw new RuntimeException("Topology with name `" + name + "` already exists on cluster"); } // Dependency uploading only makes sense for distributed mode List<String> jarsBlobKeys = Collections.emptyList(); List<String> artifactsBlobKeys; DependencyUploader uploader = new DependencyUploader(); try { uploader.init(); jarsBlobKeys = uploadDependencyJarsToBlobStore(uploader); artifactsBlobKeys = uploadDependencyArtifactsToBlobStore(uploader); } catch (Throwable e) { // remove uploaded jars blobs, not artifacts since they're shared across the cluster uploader.deleteBlobs(jarsBlobKeys); uploader.shutdown(); throw e; } try { setDependencyBlobsToTopology(topology, jarsBlobKeys, artifactsBlobKeys); submitTopologyInDistributeMode(name, topology, opts, progressListener, asUser, conf, serConf, client); } catch (AlreadyAliveException | InvalidTopologyException | AuthorizationException e) { // remove uploaded jars blobs, not artifacts since they're shared across the cluster // Note that we don't handle TException to delete jars blobs // because it's safer to leave some blobs instead of topology not running uploader.deleteBlobs(jarsBlobKeys); throw e; } finally { uploader.shutdown(); } } } } catch(TException e) { throw new RuntimeException(e); } invokeSubmitterHook(name, asUser, conf, topology); }
- submitTopologyAs of StormSubmitter creates NimbusClient through NimbusClient.getConfiguredClientAs(conf, asUser)
NimbusClient
storm-core-1.1.0-sources.jar!/org/apache/storm/utils/NimbusClient.java
public static NimbusClient getConfiguredClientAs(Map conf, String asUser) { if (conf.containsKey(Config.STORM_DO_AS_USER)) { if (asUser != null && !asUser.isEmpty()) { LOG.warn("You have specified a doAsUser as param {} and a doAsParam as config, config will take precedence." , asUser, conf.get(Config.STORM_DO_AS_USER)); } asUser = (String) conf.get(Config.STORM_DO_AS_USER); } List<String> seeds; if(conf.containsKey(Config.NIMBUS_HOST)) { LOG.warn("Using deprecated config {} for backward compatibility. Please update your storm.yaml so it only has config {}", Config.NIMBUS_HOST, Config.NIMBUS_SEEDS); seeds = Lists.newArrayList(conf.get(Config.NIMBUS_HOST).toString()); } else { seeds = (List<String>) conf.get(Config.NIMBUS_SEEDS); } for (String host : seeds) { int port = Integer.parseInt(conf.get(Config.NIMBUS_THRIFT_PORT).toString()); NimbusSummary nimbusSummary; NimbusClient client = null; try { client = new NimbusClient(conf, host, port, null, asUser); nimbusSummary = client.getClient().getLeader(); if (nimbusSummary != null) { String leaderNimbus = nimbusSummary.get_host() + ":" + nimbusSummary.get_port(); LOG.info("Found leader nimbus : {}", leaderNimbus); if (nimbusSummary.get_host().equals(host) && nimbusSummary.get_port() == port) { NimbusClient ret = client; client = null; return ret; } try { return new NimbusClient(conf, nimbusSummary.get_host(), nimbusSummary.get_port(), null, asUser); } catch (TTransportException e) { throw new RuntimeException("Failed to create a nimbus client for the leader " + leaderNimbus, e); } } } catch (Exception e) { LOG.warn("Ignoring exception while trying to get leader nimbus info from " + host + ". will retry with a different seed host.", e); continue; } finally { if (client != null) { client.close(); } } throw new NimbusLeaderNotFoundException("Could not find a nimbus leader, please try " + "again after some time."); } throw new NimbusLeaderNotFoundException( "Could not find leader nimbus from seed hosts " + seeds + ". " + "Did you specify a valid list of nimbus hosts for config " + Config.NIMBUS_SEEDS + "?"); }
- This is still compatible with the nimbus ﹣ host parameter. If there is a nimbus ﹣ host parameter, the seeds will be read from it. If there is no nimbus ﹣ host parameter, the seeds will be obtained from the nimbus ﹣ seeds parameter
- After that, traverse the seeds, create NimbusClient according to each seed, and then call client.getClient().getLeader() to get the leader information. If it succeeds, judge whether the leader is currently connected to the seed, if it is, directly return it, if not, create a new NimbusClient according to the leader's host and port to return it
- If nimbusSummary is null, a NimbusLeaderNotFoundException("Could not find a nimbus leader, please try again after some time.") is thrown
- If there is an exception in the connection leader, traverse the next seed and retry. If all seeds fail to retry, the loop will pop out, and finally the nimbusleader notfoundexception ("could not find leader nimbus from seed hosts" + seeds + ". Did you specify a valid list of nimbus hosts for config nimbus. Seeds?") will be thrown
Summary
- For storm client, the nimbus.seeds parameter is used by client to find nimbus leader, while the nimbus.host parameter has been discarded
- The process of finding a nimbus leader is to traverse the host s configured by seeds one by one, connect, and then obtain the leader information. If the acquisition succeeds but the nimbusSummary is null, a nimbusleader notfoundexception ("could not find a nimbus leader, please try again after some time.") will be thrown.
- If there is any exception, traverse the next seed for retry. If it is not successful, the loop will pop out and throw nimbusleadernotfoundexception ("could not find leader nimbus from seed hosts" + seeds + ". Did you specify a valid list of nimbus hosts for config nimbus. Seeds?")