[CCR] Auto follow pattern APIs adjustments (#34518)

* Changed the resource id of auto follow patterns to be a user defined name
instead of being the leader cluster alias name.
* Fail when an unfollowed leader index matches with two or more auto follow patterns.

x-pack/plugin/ccr/qa/multi-cluster-with-non-compliant-license/src/test/java/org/elasticsearch/xpack/ccr/CcrMultiClusterLicenseIT.java

@@ -50,8 +50,8 @@ public void testFollow() {
     public void testAutoFollow() throws Exception {
         assumeFalse("windows is the worst", Constants.WINDOWS);
         if (runningAgainstLeaderCluster == false) {
-            final Request request = new Request("PUT", "/_ccr/auto_follow/leader_cluster");
-            request.setJsonEntity("{\"leader_index_patterns\":[\"*\"]}");
+            final Request request = new Request("PUT", "/_ccr/auto_follow/test_pattern");
+            request.setJsonEntity("{\"leader_index_patterns\":[\"*\"], \"leader_cluster\": \"leader_cluster\"}");
             client().performRequest(request);
 
             // parse the logs and ensure that the auto-coordinator skipped coordination on the leader cluster
@@ -64,7 +64,7 @@ public void testAutoFollow() throws Exception {
                 while (it.hasNext()) {
                     final String line = it.next();
                     if (line.matches(".*\\[WARN\\s*\\]\\[o\\.e\\.x\\.c\\.a\\.AutoFollowCoordinator\\s*\\] \\[node-0\\] " +
-                            "failure occurred while fetching cluster state in leader cluster \\[leader_cluster\\]")) {
+                            "failure occurred while fetching cluster state for auto follow pattern \\[test_pattern\\]")) {
                         warn = true;
                         break;
                     }

x-pack/plugin/ccr/qa/multi-cluster-with-security/src/test/java/org/elasticsearch/xpack/ccr/FollowIndexSecurityIT.java

@@ -146,14 +146,14 @@ public void testAutoFollowPatterns() throws Exception {
         String disallowedIndex = "logs-us-20190101";
 
         {
-            Request request = new Request("PUT", "/_ccr/auto_follow/leader_cluster");
-            request.setJsonEntity("{\"leader_index_patterns\": [\"logs-*\"]}");
+            Request request = new Request("PUT", "/_ccr/auto_follow/test_pattern");
+            request.setJsonEntity("{\"leader_index_patterns\": [\"logs-*\"], \"leader_cluster\": \"leader_cluster\"}");
             Exception e = expectThrows(ResponseException.class, () -> assertOK(client().performRequest(request)));
             assertThat(e.getMessage(), containsString("insufficient privileges to follow index [logs-*]"));
         }
 
-        Request request = new Request("PUT", "/_ccr/auto_follow/leader_cluster");
-        request.setJsonEntity("{\"leader_index_patterns\": [\"logs-eu-*\"]}");
+        Request request = new Request("PUT", "/_ccr/auto_follow/test_pattern");
+        request.setJsonEntity("{\"leader_index_patterns\": [\"logs-eu-*\"], \"leader_cluster\": \"leader_cluster\"}");
         assertOK(client().performRequest(request));
 
         try (RestClient leaderClient = buildLeaderClient()) {
@@ -185,7 +185,7 @@ public void testAutoFollowPatterns() throws Exception {
         });
 
         // Cleanup by deleting auto follow pattern and pause following:
-        request = new Request("DELETE", "/_ccr/auto_follow/leader_cluster");
+        request = new Request("DELETE", "/_ccr/auto_follow/test_pattern");
         assertOK(client().performRequest(request));
         pauseFollow(allowedIndex);
     }

x-pack/plugin/ccr/qa/multi-cluster/src/test/java/org/elasticsearch/xpack/ccr/FollowIndexIT.java

@@ -103,8 +103,8 @@ public void testFollowNonExistingLeaderIndex() throws Exception {
     public void testAutoFollowPatterns() throws Exception {
         assumeFalse("Test should only run when both clusters are running", runningAgainstLeaderCluster);
 
-        Request request = new Request("PUT", "/_ccr/auto_follow/leader_cluster");
-        request.setJsonEntity("{\"leader_index_patterns\": [\"logs-*\"]}");
+        Request request = new Request("PUT", "/_ccr/auto_follow/test_pattern");
+        request.setJsonEntity("{\"leader_index_patterns\": [\"logs-*\"], \"leader_cluster\": \"leader_cluster\"}");
         assertOK(client().performRequest(request));
 
         try (RestClient leaderClient = buildLeaderClient()) {

x-pack/plugin/ccr/qa/rest/src/test/resources/rest-api-spec/test/ccr/auto_follow.yml

@@ -21,29 +21,32 @@
 
   - do:
       ccr.put_auto_follow_pattern:
-        leader_cluster: local
+        name: my_pattern
         body:
+          leader_cluster: local
           leader_index_patterns: ['logs-*']
           max_concurrent_read_batches: 2
   - is_true: acknowledged
 
   - do:
       ccr.get_auto_follow_pattern:
-        leader_cluster: local
-  - match: { local.leader_index_patterns: ['logs-*'] }
-  - match: { local.max_concurrent_read_batches: 2 }
+        name: my_pattern
+  - match: { my_pattern.leader_cluster: 'local' }
+  - match: { my_pattern.leader_index_patterns: ['logs-*'] }
+  - match: { my_pattern.max_concurrent_read_batches: 2 }
 
   - do:
       ccr.get_auto_follow_pattern: {}
-  - match: { local.leader_index_patterns: ['logs-*'] }
-  - match: { local.max_concurrent_read_batches: 2 }
+  - match: { my_pattern.leader_cluster: 'local' }
+  - match: { my_pattern.leader_index_patterns: ['logs-*'] }
+  - match: { my_pattern.max_concurrent_read_batches: 2 }
 
   - do:
       ccr.delete_auto_follow_pattern:
-        leader_cluster: local
+        name: my_pattern
   - is_true: acknowledged
 
   - do:
       catch: missing
       ccr.get_auto_follow_pattern:
-        leader_cluster: local
+        name: my_pattern

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/AutoFollowCoordinator.java

@@ -47,6 +47,7 @@
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
+import java.util.stream.Collectors;
 
 /**
  * A component that runs only on the elected master node and follows leader indices automatically
@@ -105,19 +106,19 @@ public synchronized AutoFollowStats getStats() {
     synchronized void updateStats(List<AutoFollowResult> results) {
         for (AutoFollowResult result : results) {
             if (result.clusterStateFetchException != null) {
-                recentAutoFollowErrors.put(result.clusterAlias,
+                recentAutoFollowErrors.put(result.autoFollowPatternName,
                     new ElasticsearchException(result.clusterStateFetchException));
                 numberOfFailedRemoteClusterStateRequests++;
-                LOGGER.warn(new ParameterizedMessage("failure occurred while fetching cluster state in leader cluster [{}]",
-                    result.clusterAlias), result.clusterStateFetchException);
+                LOGGER.warn(new ParameterizedMessage("failure occurred while fetching cluster state for auto follow pattern [{}]",
+                    result.autoFollowPatternName), result.clusterStateFetchException);
             } else {
                 for (Map.Entry<Index, Exception> entry : result.autoFollowExecutionResults.entrySet()) {
                     if (entry.getValue() != null) {
                         numberOfFailedIndicesAutoFollowed++;
-                        recentAutoFollowErrors.put(result.clusterAlias + ":" + entry.getKey().getName(),
+                        recentAutoFollowErrors.put(result.autoFollowPatternName + ":" + entry.getKey().getName(),
                             ExceptionsHelper.convertToElastic(entry.getValue()));
-                        LOGGER.warn(new ParameterizedMessage("failure occurred while auto following index [{}] in leader cluster [{}]",
-                            entry.getKey(), result.clusterAlias), entry.getValue());
+                        LOGGER.warn(new ParameterizedMessage("failure occurred while auto following index [{}] for auto follow " +
+                            "pattern [{}]", entry.getKey(), result.autoFollowPatternName), entry.getValue());
                     } else {
                         numberOfSuccessfulIndicesAutoFollowed++;
                     }
@@ -243,51 +244,77 @@ void autoFollowIndices() {
             int i = 0;
             for (Map.Entry<String, AutoFollowPattern> entry : autoFollowMetadata.getPatterns().entrySet()) {
                 final int slot = i;
-                final String clusterAlias = entry.getKey();
+                final String autoFollowPattenName = entry.getKey();
                 final AutoFollowPattern autoFollowPattern = entry.getValue();
+                final String leaderCluster = autoFollowPattern.getLeaderCluster();
 
-                Map<String, String> headers = autoFollowMetadata.getHeaders().get(clusterAlias);
-                getLeaderClusterState(headers, clusterAlias, (leaderClusterState, e) -> {
+                Map<String, String> headers = autoFollowMetadata.getHeaders().get(autoFollowPattenName);
+                getLeaderClusterState(headers, leaderCluster, (leaderClusterState, e) -> {
                     if (leaderClusterState != null) {
                         assert e == null;
-                        final List<String> followedIndices = autoFollowMetadata.getFollowedLeaderIndexUUIDs().get(clusterAlias);
-                        final List<Index> leaderIndicesToFollow = getLeaderIndicesToFollow(clusterAlias, autoFollowPattern,
+                        final List<String> followedIndices = autoFollowMetadata.getFollowedLeaderIndexUUIDs().get(autoFollowPattenName);
+                        final List<Index> leaderIndicesToFollow = getLeaderIndicesToFollow(leaderCluster, autoFollowPattern,
                             leaderClusterState, followerClusterState, followedIndices);
                         if (leaderIndicesToFollow.isEmpty()) {
-                            finalise(slot, new AutoFollowResult(clusterAlias));
+                            finalise(slot, new AutoFollowResult(autoFollowPattenName));
                         } else {
+                            List<Tuple<String, AutoFollowPattern>> patternsForTheSameLeaderCluster = autoFollowMetadata.getPatterns()
+                                .entrySet().stream()
+                                .filter(item -> autoFollowPattenName.equals(item.getKey()) == false)
+                                .filter(item -> leaderCluster.equals(item.getValue().getLeaderCluster()))
+                                .map(item -> new Tuple<>(item.getKey(), item.getValue()))
+                                .collect(Collectors.toList());
+
                             Consumer<AutoFollowResult> resultHandler = result -> finalise(slot, result);
-                            checkAutoFollowPattern(clusterAlias, autoFollowPattern, leaderIndicesToFollow, headers, resultHandler);
+                            checkAutoFollowPattern(autoFollowPattenName, leaderCluster, autoFollowPattern, leaderIndicesToFollow, headers,
+                                patternsForTheSameLeaderCluster, resultHandler);
                         }
                     } else {
-                        finalise(slot, new AutoFollowResult(clusterAlias, e));
+                        finalise(slot, new AutoFollowResult(autoFollowPattenName, e));
                     }
                 });
                 i++;
             }
         }
 
-        private void checkAutoFollowPattern(String clusterAlias,
+        private void checkAutoFollowPattern(String autoFollowPattenName,
+                                            String clusterAlias,
                                             AutoFollowPattern autoFollowPattern,
                                             List<Index> leaderIndicesToFollow,
                                             Map<String, String> headers,
+                                            List<Tuple<String, AutoFollowPattern>> patternsForTheSameLeaderCluster,
                                             Consumer<AutoFollowResult> resultHandler) {
 
             final CountDown leaderIndicesCountDown = new CountDown(leaderIndicesToFollow.size());
             final AtomicArray<Tuple<Index, Exception>> results = new AtomicArray<>(leaderIndicesToFollow.size());
             for (int i = 0; i < leaderIndicesToFollow.size(); i++) {
                 final Index indexToFollow = leaderIndicesToFollow.get(i);
                 final int slot = i;
-                followLeaderIndex(clusterAlias, indexToFollow, autoFollowPattern, headers, error -> {
-                    results.set(slot, new Tuple<>(indexToFollow, error));
+
+                List<String> otherMatchingPatterns = patternsForTheSameLeaderCluster.stream()
+                    .filter(otherPattern -> otherPattern.v2().match(indexToFollow.getName()))
+                    .map(Tuple::v1)
+                    .collect(Collectors.toList());
+                if (otherMatchingPatterns.size() != 0) {
+                    results.set(slot, new Tuple<>(indexToFollow, new ElasticsearchException("index to follow [" + indexToFollow.getName() +
+                        "] for pattern [" + autoFollowPattenName + "] matches with other patterns " + otherMatchingPatterns + "")));
                     if (leaderIndicesCountDown.countDown()) {
-                        resultHandler.accept(new AutoFollowResult(clusterAlias, results.asList()));
+                        resultHandler.accept(new AutoFollowResult(autoFollowPattenName, results.asList()));
                     }
-                });
+                } else {
+                    followLeaderIndex(autoFollowPattenName, clusterAlias, indexToFollow, autoFollowPattern, headers, error -> {
+                        results.set(slot, new Tuple<>(indexToFollow, error));
+                        if (leaderIndicesCountDown.countDown()) {
+                            resultHandler.accept(new AutoFollowResult(autoFollowPattenName, results.asList()));
+                        }
+                    });
+                }
+
             }
         }
 
-        private void followLeaderIndex(String clusterAlias,
+        private void followLeaderIndex(String autoFollowPattenName,
+                                       String clusterAlias,
                                        Index indexToFollow,
                                        AutoFollowPattern pattern,
                                        Map<String,String> headers,
@@ -313,7 +340,7 @@ private void followLeaderIndex(String clusterAlias,
 
                 // This function updates the auto follow metadata in the cluster to record that the leader index has been followed:
                 // (so that we do not try to follow it in subsequent auto follow runs)
-                Function<ClusterState, ClusterState> function = recordLeaderIndexAsFollowFunction(clusterAlias, indexToFollow);
+                Function<ClusterState, ClusterState> function = recordLeaderIndexAsFollowFunction(autoFollowPattenName, indexToFollow);
                 // The coordinator always runs on the elected master node, so we can update cluster state here:
                 updateAutoFollowMetadata(function, onResult);
             };
@@ -356,12 +383,12 @@ static String getFollowerIndexName(AutoFollowPattern autoFollowPattern, String l
             }
         }
 
-        static Function<ClusterState, ClusterState> recordLeaderIndexAsFollowFunction(String clusterAlias,
+        static Function<ClusterState, ClusterState> recordLeaderIndexAsFollowFunction(String name,
                                                                                       Index indexToFollow) {
             return currentState -> {
                 AutoFollowMetadata currentAutoFollowMetadata = currentState.metaData().custom(AutoFollowMetadata.TYPE);
                 Map<String, List<String>> newFollowedIndexUUIDS = new HashMap<>(currentAutoFollowMetadata.getFollowedLeaderIndexUUIDs());
-                newFollowedIndexUUIDS.compute(clusterAlias, (key, existingUUIDs) -> {
+                newFollowedIndexUUIDS.compute(name, (key, existingUUIDs) -> {
                     assert existingUUIDs != null;
                     List<String> newUUIDs = new ArrayList<>(existingUUIDs);
                     newUUIDs.add(indexToFollow.getUUID());
@@ -405,12 +432,12 @@ abstract void updateAutoFollowMetadata(
 
     static class AutoFollowResult {
 
-        final String clusterAlias;
+        final String autoFollowPatternName;
         final Exception clusterStateFetchException;
         final Map<Index, Exception> autoFollowExecutionResults;
 
-        AutoFollowResult(String clusterAlias, List<Tuple<Index, Exception>> results) {
-            this.clusterAlias = clusterAlias;
+        AutoFollowResult(String autoFollowPatternName, List<Tuple<Index, Exception>> results) {
+            this.autoFollowPatternName = autoFollowPatternName;
 
             Map<Index, Exception> autoFollowExecutionResults = new HashMap<>();
             for (Tuple<Index, Exception> result : results) {
@@ -421,14 +448,14 @@ static class AutoFollowResult {
             this.autoFollowExecutionResults = Collections.unmodifiableMap(autoFollowExecutionResults);
         }
 
-        AutoFollowResult(String clusterAlias, Exception e) {
-            this.clusterAlias = clusterAlias;
+        AutoFollowResult(String autoFollowPatternName, Exception e) {
+            this.autoFollowPatternName = autoFollowPatternName;
             this.clusterStateFetchException = e;
             this.autoFollowExecutionResults = Collections.emptyMap();
         }
 
-        AutoFollowResult(String clusterAlias) {
-            this(clusterAlias, (Exception) null);
+        AutoFollowResult(String autoFollowPatternName) {
+            this(autoFollowPatternName, (Exception) null);
         }
     }
 }

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportDeleteAutoFollowPatternAction.java

@@ -54,7 +54,7 @@ protected AcknowledgedResponse newResponse() {
     protected void masterOperation(DeleteAutoFollowPatternAction.Request request,
                                    ClusterState state,
                                    ActionListener<AcknowledgedResponse> listener) throws Exception {
-        clusterService.submitStateUpdateTask("put-auto-follow-pattern-" + request.getLeaderCluster(),
+        clusterService.submitStateUpdateTask("put-auto-follow-pattern-" + request.getName(),
             new AckedClusterStateUpdateTask<AcknowledgedResponse>(request, listener) {
 
             @Override
@@ -72,23 +72,23 @@ public ClusterState execute(ClusterState currentState) throws Exception {
     static ClusterState innerDelete(DeleteAutoFollowPatternAction.Request request, ClusterState currentState) {
         AutoFollowMetadata currentAutoFollowMetadata = currentState.metaData().custom(AutoFollowMetadata.TYPE);
         if (currentAutoFollowMetadata == null) {
-            throw new ResourceNotFoundException("no auto-follow patterns for cluster alias [{}] found",
-                request.getLeaderCluster());
+            throw new ResourceNotFoundException("auto-follow pattern [{}] is missing",
+                request.getName());
         }
         Map<String, AutoFollowPattern> patterns = currentAutoFollowMetadata.getPatterns();
-        AutoFollowPattern autoFollowPatternToRemove = patterns.get(request.getLeaderCluster());
+        AutoFollowPattern autoFollowPatternToRemove = patterns.get(request.getName());
         if (autoFollowPatternToRemove == null) {
-            throw new ResourceNotFoundException("no auto-follow patterns for cluster alias [{}] found",
-                request.getLeaderCluster());
+            throw new ResourceNotFoundException("auto-follow pattern [{}] is missing",
+                request.getName());
         }
 
         final Map<String, AutoFollowPattern> patternsCopy = new HashMap<>(patterns);
         final Map<String, List<String>> followedLeaderIndexUUIDSCopy =
             new HashMap<>(currentAutoFollowMetadata.getFollowedLeaderIndexUUIDs());
         final Map<String, Map<String, String>> headers = new HashMap<>(currentAutoFollowMetadata.getHeaders());
-        patternsCopy.remove(request.getLeaderCluster());
-        followedLeaderIndexUUIDSCopy.remove(request.getLeaderCluster());
-        headers.remove(request.getLeaderCluster());
+        patternsCopy.remove(request.getName());
+        followedLeaderIndexUUIDSCopy.remove(request.getName());
+        headers.remove(request.getName());
 
         AutoFollowMetadata newAutoFollowMetadata = new AutoFollowMetadata(patternsCopy, followedLeaderIndexUUIDSCopy, headers);
         ClusterState.Builder newState = ClusterState.builder(currentState);