SERVER-4905: add flag to disable mongo's builtin log rotation

To support the standalone utility, we need to give administrators
support for disabling Mongo's builtin log rotation.

3 files changed, 12 insertions, 4 deletions

diff --git a/src/mongo/util/log.cpp b/src/mongo/util/log.cpp
index ebf7556f109..bd0af52aac7 100644
--- a/src/mongo/util/log.cpp
+++ b/src/mongo/util/log.cpp
@@ -66,11 +66,11 @@ namespace mongo {
         return Status::OK();
     }
 
-    bool rotateLogs() {
+    bool rotateLogs(bool renameFiles) {
         using logger::RotatableFileManager;
         RotatableFileManager* manager = logger::globalRotatableFileManager();
         RotatableFileManager::FileNameStatusPairVector result(
-                manager->rotateAll("." + terseCurrentTime(false)));
+                manager->rotateAll(renameFiles, "." + terseCurrentTime(false)));
         for (RotatableFileManager::FileNameStatusPairVector::iterator it = result.begin();
                 it != result.end(); it++) {
             warning() << "Rotating log file " << it->first << " failed: " << it->second.toString()
diff --git a/src/mongo/util/log.h b/src/mongo/util/log.h
index b61913a0d32..ab221bd01da 100644
--- a/src/mongo/util/log.h
+++ b/src/mongo/util/log.h
@@ -93,8 +93,16 @@ namespace logger {
 
     /**
      * Rotates the log files.  Returns true if all logs rotate successfully.
+     *
+     * renameFiles - true means we rename files, false means we expect the file to be renamed
+     *               externally
+     *
+     * logrotate on *nix systems expects us not to rename the file, it is expected that the program
+     * simply open the file again with the same name.
+     * We expect logrotate to rename the existing file before we rotate, and so the next open
+     * we do should result in a file create.
      */
-    bool rotateLogs();
+    bool rotateLogs(bool renameFiles);
 
     /** output the error # and error message with prefix.
         handy for use as parm in uassert/massert.
diff --git a/src/mongo/util/signal_handlers.cpp b/src/mongo/util/signal_handlers.cpp
index 8d15ef4e912..863e946f045 100644
--- a/src/mongo/util/signal_handlers.cpp
+++ b/src/mongo/util/signal_handlers.cpp
@@ -306,7 +306,7 @@ namespace {
             switch (actualSignal) {
             case SIGUSR1:
                 // log rotate signal
-                fassert(16782, rotateLogs());
+                fassert(16782, rotateLogs(serverGlobalParams.logRenameOnRotate));
                 logProcessDetailsForLogRotate();
                 break;
             case SIGQUIT: