SERVER-11688 Improve diagnostic messages for metadata reloading in shards

Signed-off-by: Matt Kangas <matt.kangas@mongodb.com>

1 files changed, 29 insertions, 17 deletions

diff --git a/src/mongo/s/d_state.cpp b/src/mongo/s/d_state.cpp
index bee870919e9..00a2e4cfb04 100644
--- a/src/mongo/s/d_state.cpp
+++ b/src/mongo/s/d_state.cpp
@@ -635,21 +635,19 @@ namespace mongo {
         //
         // Do messaging based on what happened above
         //
-
-        string versionMsg = str::stream()
-            << " (loaded metadata version : " << remoteCollVersion.toString()
-            << ( beforeCollVersion.epoch() == afterCollVersion.epoch() ?
-                     string( ", stored version : " ) + afterCollVersion.toString() :
-                     string( ", stored versions : " ) +
-                         beforeCollVersion.toString() + " / " + afterCollVersion.toString() )
-            << ", took " << refreshMillis << "ms)";
+        string localShardVersionMsg =
+                beforeShardVersion.epoch() == afterShardVersion.epoch() ?
+                        afterShardVersion.toString() :
+                        beforeShardVersion.toString() + " / " + afterShardVersion.toString();
 
         if ( choice == ChunkVersion::VersionChoice_Unknown ) {
 
-            string errMsg =
-                str::stream() << "need to retry loading metadata for " << ns
-                              << ", collection may have been dropped or recreated during load"
-                              << versionMsg;
+            string errMsg = str::stream()
+                << "need to retry loading metadata for " << ns
+                << ", collection may have been dropped or recreated during load"
+                << " (loaded shard version : " << remoteShardVersion.toString()
+                << ", stored shard versions : " << localShardVersionMsg
+                << ", took " << refreshMillis << "ms)";
 
             warning() << errMsg << endl;
             return Status( ErrorCodes::RemoteChangeDetected, errMsg );
@@ -657,7 +655,9 @@ namespace mongo {
 
         if ( choice == ChunkVersion::VersionChoice_Local ) {
 
-            LOG( 0 ) << "newer metadata not found for " << ns << versionMsg << endl;
+            LOG( 0 ) << "metadata of collection " << ns << " already up to date (shard version : "
+                     << afterShardVersion.toString() << ", took " << refreshMillis << "ms)"
+                     << endl;
             return Status::OK();
         }
 
@@ -665,22 +665,34 @@ namespace mongo {
 
         switch( installType ) {
         case InstallType_New:
-            LOG( 0 ) << "loaded new metadata for " << ns << versionMsg << endl;
+            LOG( 0 ) << "collection " << ns << " was previously unsharded"
+                     << ", new metadata loaded with shard version " << remoteShardVersion
+                     << endl;
             break;
         case InstallType_Update:
-            LOG( 0 ) << "loaded newer metadata for " << ns << versionMsg << endl;
+            LOG( 0 ) << "updating metadata for " << ns << " from shard version "
+                     << localShardVersionMsg << " to shard version " << remoteShardVersion
+                     << endl;
             break;
         case InstallType_Replace:
-            LOG( 0 ) << "replacing metadata for " << ns << versionMsg << endl;
+            LOG( 0 ) << "replacing metadata for " << ns << " at shard version "
+                     << localShardVersionMsg << " with a new epoch (shard version "
+                     << remoteShardVersion << ")" << endl;
             break;
         case InstallType_Drop:
-            LOG( 0 ) << "dropping metadata for " << ns << versionMsg << endl;
+            LOG( 0 ) << "dropping metadata for " << ns << " at shard version "
+                     << localShardVersionMsg << ", took " << refreshMillis << "ms" << endl;
             break;
         default:
             verify( false );
             break;
         }
 
+        if ( installType != InstallType_Drop ) {
+            LOG( 0 ) << "collection version was loaded at version " << remoteCollVersion
+                     << ", took " << refreshMillis << "ms" << endl;
+        }
+
         return Status::OK();
     }