frnidito commented on a change in pull request #8987: Adding support for autoscaling in GCE URL: https://github.com/apache/druid/pull/8987#discussion_r380266518
########## File path: extensions-contrib/gce-extensions/src/main/java/org/apache/druid/indexing/overlord/autoscaling/gce/GCEAutoScaler.java ########## @@ -0,0 +1,496 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.druid.indexing.overlord.autoscaling.gce; + +import com.fasterxml.jackson.annotation.JacksonInject; +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.fasterxml.jackson.annotation.JsonTypeName; +import com.google.api.client.googleapis.auth.oauth2.GoogleCredential; +import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport; +import com.google.api.client.http.HttpTransport; +import com.google.api.client.json.JsonFactory; +import com.google.api.client.json.jackson2.JacksonFactory; +import com.google.api.services.compute.Compute; +import com.google.api.services.compute.ComputeScopes; +import com.google.api.services.compute.model.Instance; +import com.google.api.services.compute.model.InstanceGroupManagersDeleteInstancesRequest; +import com.google.api.services.compute.model.InstanceGroupManagersListManagedInstancesResponse; +import com.google.api.services.compute.model.InstanceList; +import com.google.api.services.compute.model.ManagedInstance; +import com.google.api.services.compute.model.Operation; +import com.google.common.net.InetAddresses; +import org.apache.druid.indexing.overlord.autoscaling.AutoScaler; +import org.apache.druid.indexing.overlord.autoscaling.AutoScalingData; +import org.apache.druid.indexing.overlord.autoscaling.SimpleWorkerProvisioningConfig; +import org.apache.druid.java.util.emitter.EmittingLogger; + +import java.io.IOException; +import java.security.GeneralSecurityException; +import java.util.ArrayList; +import java.util.List; +import java.util.Locale; + +/** + * This module permits the autoscaling of the workers in GCE + * + * General notes: + * - The IPs are IPs as in Internet Protocol, and they look like 1.2.3.4 + * - The IDs are the names of the instances of instances created, they look like prefix-abcd, + * where the prefix is chosen by you and abcd is a suffix assigned by GCE + */ +@JsonTypeName("gce") +public class GCEAutoScaler implements AutoScaler<GCEEnvironmentConfig> +{ + private static final EmittingLogger log = new EmittingLogger(GCEAutoScaler.class); + + private final GCEEnvironmentConfig envConfig; + private final int minNumWorkers; + private final int maxNumWorkers; + private final SimpleWorkerProvisioningConfig config; // For future use + + private Compute cachedComputeService = null; + + @JsonCreator + public GCEAutoScaler( + @JsonProperty("minNumWorkers") int minNumWorkers, + @JsonProperty("maxNumWorkers") int maxNumWorkers, + @JsonProperty("envConfig") GCEEnvironmentConfig envConfig, + @JacksonInject SimpleWorkerProvisioningConfig config + ) + { + this.minNumWorkers = minNumWorkers; + this.maxNumWorkers = maxNumWorkers; + this.envConfig = envConfig; + this.config = config; + } + + /** + * CAVEAT: this is meant to be used only for testing passing a mock version of Compute + */ + public GCEAutoScaler( + int minNumWorkers, + int maxNumWorkers, + GCEEnvironmentConfig envConfig, + SimpleWorkerProvisioningConfig config, + Compute compute + ) + { + this(minNumWorkers, maxNumWorkers, envConfig, config); + this.cachedComputeService = compute; + } + + @Override + @JsonProperty + public int getMinNumWorkers() + { + return minNumWorkers; + } + + @Override + @JsonProperty + public int getMaxNumWorkers() + { + return maxNumWorkers; + } + + @Override + @JsonProperty + public GCEEnvironmentConfig getEnvConfig() + { + return envConfig; + } + + private synchronized Compute createComputeService() + throws IOException, GeneralSecurityException, InterruptedException + { + final int max_retries = 5; + final long retries_interval = 5 * 1000; // 5 secs. + + int retries = 0; + while (cachedComputeService == null && retries < max_retries) { + if (retries > 0) { + Thread.sleep(retries_interval); + } + + log.info("Creating new ComputeService [%d/%d]", retries + 1, max_retries); + + try { + HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport(); + JsonFactory jsonFactory = JacksonFactory.getDefaultInstance(); + GoogleCredential credential = GoogleCredential.getApplicationDefault( + httpTransport, + jsonFactory + ); + if (credential.createScopedRequired()) { + List<String> scopes = new ArrayList<>(); + scopes.add(ComputeScopes.CLOUD_PLATFORM); + scopes.add(ComputeScopes.COMPUTE); + credential = credential.createScoped(scopes); + } + + if (credential.getClientAuthentication() != null) { + log.error("Not using a service account, terminating"); + System.exit(1); + } + + cachedComputeService = new Compute.Builder(httpTransport, jsonFactory, credential) + .setApplicationName("DruidAutoscaler") + .build(); + + retries++; + } + catch (Throwable e) { + log.error(e, "Got Exception in creating the ComputeService"); + throw e; + } + } + return cachedComputeService; + } + + // Used to wait for an operation to finish + private Operation.Error waitForOperationEnd( + Compute compute, + Operation operation) throws Exception + { + final long pollInterval = 5 * 1000; // 5 sec + + String status = operation.getStatus(); + String opId = operation.getName(); + while (operation != null && !"DONE".equals(status)) { + Thread.sleep(pollInterval); + Compute.ZoneOperations.Get get = compute.zoneOperations().get( + envConfig.getProjectId(), + envConfig.getZoneName(), + opId + ); + operation = get.execute(); + if (operation != null) { + status = operation.getStatus(); + } + } + return operation == null ? null : operation.getError(); + } + + /** + * When called resizes envConfig.getManagedInstanceGroupName() increasing it by creating + * envConfig.getNumInstances() new workers (unless the maximum is reached). Return the + * IDs of the workers created + */ + @Override + public AutoScalingData provision() + { + final String project = envConfig.getProjectId(); + final String zone = envConfig.getZoneName(); + final int numInstances = envConfig.getNumInstances(); + final String managedInstanceGroupName = envConfig.getManagedInstanceGroupName(); + + try { + List<String> before = getRunningInstances(); + log.debug("Existing instances [%s]", String.join(",", before)); + + int toSize = Math.min(before.size() + numInstances, getMaxNumWorkers()); + if (before.size() >= toSize) { + // nothing to scale + return new AutoScalingData(new ArrayList<>()); + } + log.info("Asked to provision instances, will resize to %d", toSize); + + Compute computeService = createComputeService(); + Compute.InstanceGroupManagers.Resize request = + computeService.instanceGroupManagers().resize(project, zone, + managedInstanceGroupName, toSize); + + Operation response = request.execute(); + Operation.Error err = waitForOperationEnd(computeService, response); + if (err == null || err.isEmpty()) { + List<String> after = getRunningInstances(); + after.removeAll(before); // these should be the new ones + log.debug("Added instances [%s]", String.join(",", after)); + return new AutoScalingData(after); + } else { + log.error("Unable to provision instances: %s", err.toPrettyString()); + } + } + catch (Exception e) { + log.error(e, "Unable to provision any gce instances."); + } + + return new AutoScalingData(new ArrayList<>()); + } + + /** + * Terminats the instances in the list of IPs provided by the caller + */ + @Override + public AutoScalingData terminate(List<String> ips) + { + log.info("Asked to terminate: [%s]", String.join(",", ips)); + + if (ips.isEmpty()) { + return new AutoScalingData(new ArrayList<>()); + } + + List<String> nodeIds = ipToIdLookup(ips); // if they are not IPs, they will be unchanged + try { + return new AutoScalingData(idToIpLookup( + terminateWithIds(nodeIds != null ? nodeIds : new ArrayList<>()).getNodeIds()) + ); + } + catch (Exception e) { + log.error(e, "Unable to terminate any instances."); + } + + return new AutoScalingData(new ArrayList<>()); + } + + private List<String> namesToInstances(List<String> names) + { + List<String> instances = new ArrayList<>(); + for (String name : names) { + instances.add( + // convert the name into a URL's path to be used in calls to the API + String.format(Locale.US, "zones/%s/instances/%s", envConfig.getZoneName(), name) + ); + } + return instances; + } + + /** + * Terminats the instances in the list of IDs provided by the caller + */ + @Override + public AutoScalingData terminateWithIds(List<String> ids) + { + log.info("Asked to terminate IDs: [%s]", String.join(",", ids)); + + if (ids.isEmpty()) { + return new AutoScalingData(new ArrayList<>()); + } + + try { + final String project = envConfig.getProjectId(); + final String zone = envConfig.getZoneName(); + final String managedInstanceGroupName = envConfig.getManagedInstanceGroupName(); + + List<String> before = getRunningInstances(); + + InstanceGroupManagersDeleteInstancesRequest requestBody = + new InstanceGroupManagersDeleteInstancesRequest(); + requestBody.setInstances(namesToInstances(ids)); + + Compute computeService = createComputeService(); + Compute.InstanceGroupManagers.DeleteInstances request = + computeService + .instanceGroupManagers() + .deleteInstances(project, zone, managedInstanceGroupName, requestBody); + + Operation response = request.execute(); + Operation.Error err = waitForOperationEnd(computeService, response); + if (err == null || err.isEmpty()) { + List<String> after = getRunningInstances(); + before.removeAll(after); // keep only the ones no more present + return new AutoScalingData(before); + } else { + log.error("Unable to terminate instances: %s", err.toPrettyString()); + } + } + catch (Exception e) { + log.error(e, "Unable to terminate any instances."); + } + + return new AutoScalingData(new ArrayList<>()); + } + + // Returns the list of the IDs of the machines running in the MIG + private List<String> getRunningInstances() + { + ArrayList<String> ids = new ArrayList<>(); + try { + final String project = envConfig.getProjectId(); + final String zone = envConfig.getZoneName(); + final String managedInstanceGroupName = envConfig.getManagedInstanceGroupName(); + + Compute computeService = createComputeService(); + Compute.InstanceGroupManagers.ListManagedInstances request = + computeService + .instanceGroupManagers() + .listManagedInstances(project, zone, managedInstanceGroupName); + // Notice that while the doc says otherwise, there is not nextPageToken to page + // through results and so everything needs to be in the same page + request.setMaxResults(500L); // 500 is sadly the max + InstanceGroupManagersListManagedInstancesResponse response = request.execute(); + for (ManagedInstance mi : response.getManagedInstances()) { + ids.add(GCEUtils.extractNameFromInstance(mi.getInstance())); + } + log.debug("Found running instances [%s]", String.join(",", ids)); + } + catch (Exception e) { + log.error(e, "Unable to get instances."); + } + return ids; + } + + /** + * Converts the IPs to IDs + */ + @Override + public List<String> ipToIdLookup(List<String> ips) + { + log.debug("Asked IPs -> IDs for: [%s]", String.join(",", ips)); + + if (ips.isEmpty()) { + return new ArrayList<>(); + } + + // If the first one is not an IP, just assume all the other ones are not as well and just + // return them as they are. This check is here because Druid does not check if IPs are + // actually IPs and can send IDs to this function instead Review comment: As far as I understood digging into the code, the underlying code seems to assume that the machines register themselves to Zookeeper with IPs but it never checks if this is *really* the case and just assumes that they are IPs--and the IPs of the workers is just stored as a string. This was noticed at the very beginning when implementing this module: if working with machine names and returning IPs the overlord was always failing when waiting for the instances to come up as the names returned by this module and the ones found in Zookeeper never matched. In practice, the caller passes around things assuming that they are IPs even when they are not and for this reason all the various operations are meant to be resilient to that behaviour. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
