SERVER-37578 Assert that a zone is associated with a shard during shard collection

2 files changed, 27 insertions, 2 deletions

diff --git a/src/mongo/db/s/config/initial_split_policy.cpp b/src/mongo/db/s/config/initial_split_policy.cpp
index 67db0084bcc..5b0af255a05 100644
--- a/src/mongo/db/s/config/initial_split_policy.cpp
+++ b/src/mongo/db/s/config/initial_split_policy.cpp
@@ -232,13 +232,24 @@ InitialSplitPolicy::generateShardCollectionInitialZonedChunks(
             const ShardId shardId = allShardIds[indx++ % allShardIds.size()];
             appendChunk(nss, lastChunkMax, tag.getMinKey(), &version, validAfter, shardId, &chunks);
         }
-        // create a chunk for the zone
+
+        // check that this tag is associated with a shard and if so create a chunk for the zone.
+        const auto& shardIdsForChunk = tagToShards.find(tag.getTag())->second;
+        uassert(50973,
+                str::stream()
+                    << "cannot shard collection "
+                    << tag.getNS().ns()
+                    << " because it is associated with zone: "
+                    << tag.getTag()
+                    << " which is not associated with a shard. please add this zone to a shard.",
+                !shardIdsForChunk.empty());
+
         appendChunk(nss,
                     tag.getMinKey(),
                     tag.getMaxKey(),
                     &version,
                     validAfter,
-                    tagToShards.find(tag.getTag())->second[0],
+                    shardIdsForChunk[0],
                     &chunks);
         lastChunkMax = tag.getMaxKey();
     }
diff --git a/src/mongo/db/s/config/initial_split_policy_test.cpp b/src/mongo/db/s/config/initial_split_policy_test.cpp
index a7a039f58b0..837d690900b 100644
--- a/src/mongo/db/s/config/initial_split_policy_test.cpp
+++ b/src/mongo/db/s/config/initial_split_policy_test.cpp
@@ -430,5 +430,19 @@ TEST_F(GenerateShardCollectionInitialZonedChunksTest, EmptyTagsShouldFail) {
         ErrorCodes::InvalidOptions);
 }
 
+TEST_F(GenerateShardCollectionInitialZonedChunksTest, ZoneNotAssociatedWithAnyShardShouldFail) {
+    const std::vector<TagsType> tags = {
+        makeTag(ChunkRange(keyPattern().globalMin(), BSON(shardKey() << 0)), zoneName("0")),
+        makeTag(ChunkRange(BSON(shardKey() << 0), keyPattern().globalMax()), zoneName("1"))};
+    StringMap<std::vector<ShardId>> tagToShards = {{zoneName("0"), {shardId("Shard0")}},
+                                                   {zoneName("1"), {}}};
+
+    ASSERT_THROWS_CODE(
+        InitialSplitPolicy::generateShardCollectionInitialZonedChunks(
+            nss(), shardKeyPattern(), timeStamp(), tags, tagToShards, makeShardIds(1)),
+        AssertionException,
+        50973);
+}
+
 }  // namespace
 }  // namespace mongo