From 970407c6632ab8330761c6f7e202d5ae9e9f2a35 Mon Sep 17 00:00:00 2001 From: Luca Cavanna Date: Tue, 25 Sep 2018 14:03:07 +0200 Subject: [PATCH] [DOCS] add comment to clarify cluster name resolution (#34014) We currently fallback to local indices whenever a remote cluster is not found, as there may still be indices / aliases with the same name. Such behaviour is lenient but needs to be kept for backwards compatibility. Clarified that in the code so we don't forget. Relates to #26247 --- .../elasticsearch/transport/RemoteClusterAware.java | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java b/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java index f75d01a0233bd..ed4875238c0bc 100644 --- a/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java +++ b/server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java @@ -231,9 +231,10 @@ public Map> groupClusterIndices(String[] requestIndices, Pr List clusters = clusterNameResolver.resolveClusterNames(remoteClusterNames, remoteClusterName); if (clusters.isEmpty() == false) { if (indexExists.test(index)) { - // we use : as a separator for remote clusters. might conflict if there is an index that is actually named - // remote_cluster_alias:index_name - for this case we fail the request. the user can easily change the cluster alias - // if that happens + //We use ":" as a separator for remote clusters. There may be a conflict if there is an index that is named + //remote_cluster_alias:index_name - for this case we fail the request. The user can easily change the cluster alias + //if that happens. Note that indices and aliases can be created with ":" in their names names up to 6.last, which + //means such names need to be supported until 7.last. It will be possible to remove this check from 8.0 on. throw new IllegalArgumentException("Can not filter indices; index " + index + " exists but there is also a remote cluster named: " + remoteClusterName); } @@ -242,6 +243,9 @@ public Map> groupClusterIndices(String[] requestIndices, Pr perClusterIndices.computeIfAbsent(clusterName, k -> new ArrayList<>()).add(indexName); } } else { + //Indices and aliases can be created with ":" in their names up to 6.last (although deprecated), and still be + //around in 7.x. That's why we need to be lenient here and treat the index as local although it contains ":". + //It will be possible to remove such leniency and assume that no local indices contain ":" only from 8.0 on. perClusterIndices.computeIfAbsent(RemoteClusterAware.LOCAL_CLUSTER_GROUP_KEY, k -> new ArrayList<>()).add(index); } } else {