SERVER-16313 make override of checkpointDelaySecs with syncdelay work properly

2 files changed, 15 insertions, 8 deletions

diff --git a/src/mongo/db/mongod_options.cpp b/src/mongo/db/mongod_options.cpp
index a2f51409547..a779db2ac57 100644
--- a/src/mongo/db/mongod_options.cpp
+++ b/src/mongo/db/mongod_options.cpp
@@ -226,6 +226,8 @@ namespace mongo {
                 moe::Double,
                 "seconds between disk syncs (0=never, but not recommended)",
                 "storage.syncPeriodSecs")
+            // Note: this default is used by checkpointDelaySecs in WiredTiger options.
+            // Be careful changing this value.
                                          .setDefault(moe::Value(60.0));
 
         // Upgrade and repair are disallowed in JSON configs since they trigger very heavyweight
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_options_init.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_options_init.cpp
index e72c08ce231..db02d9f1951 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_options_init.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_options_init.cpp
@@ -43,14 +43,19 @@ namespace mongo {
 
         // Make --syncdelay (syncPeriodSecs in mmapv1) an alias for checkpointDelaySecs in WT
         moe::Value syncdelayVal;
-        if (moe::startupOptionsParsed.get("storage.mmapv1.syncPeriodSecs", &syncdelayVal).isOK()) {
-            // syncdelay is a double but checkpointDelaySecs is an int.
-            moe::Value newVal(static_cast<int>(syncdelayVal.as<double>()));
-            Status ret = moe::startupOptionsParsed.set(
-                "storage.wiredTiger.engineConfig.checkpointDelaySecs", newVal);
-            if (!ret.isOK()) {
-                return ret;
-            }
+        // syncPeriodSecs is always set since it has a default.
+        invariant(moe::startupOptionsParsed.get("storage.mmapv1.syncPeriodSecs",
+                                                &syncdelayVal).isOK());
+        // Ignore override if set to default of 60.
+        if (syncdelayVal.equal(moe::Value(60.0))) {
+            return Status::OK();
+        }
+        // syncdelay is a double but checkpointDelaySecs is an int.
+        moe::Value newVal(static_cast<int>(syncdelayVal.as<double>()));
+        Status ret = moe::startupOptionsParsed.set(
+            "storage.wiredTiger.engineConfig.checkpointDelaySecs", newVal);
+        if (!ret.isOK()) {
+            return ret;
         }
         return Status::OK();
     }