prime the sam ldb schema in the parent samba process

While testing the use of the standard process model with 'make test' I
found that testing was much slower (by several times) with the
standard model than with the single model. The primary problem was
that each SMB connection would open a new sam ldb context, and all of
those would reload the full AD schema.

The fix is to pre-open the SAM during server startup, before any child
processes are forked. This sets up the global schema context which is
inherited by all connections.

The standard model is still slower at make test than the single model,
but not by nearly as much. I am working on further reducing the gap.

diff --git a/source4/smbd/server.c b/source4/smbd/server.c
index 635e84fafecfd718949db42382fe2b25e41a3202..bb2571e8194de16cf1f38e10984bd6715d51d64a 100644 (file)
--- a/source4/smbd/server.c
+++ b/source4/smbd/server.c
@@ -38,6 +38,8 @@
 #include "param/secrets.h"
 #include "smbd/pidfile.h"
 #include "param/param.h"
+#include "dsdb/samdb/samdb.h"
+#include "auth/session.h"
 
 /*
   recursively delete a directory tree
@@ -112,6 +114,7 @@ static void sig_term(int sig)
                kill(-getpgrp(), SIGTERM);
        }
 #endif
+       DEBUG(0,("Exiting pid %d on SIGTERM\n", (int)getpid()));
        exit(0);
 }
 
@@ -157,6 +160,7 @@ static void server_stdin_handler(struct tevent_context *event_ctx, struct tevent
                DEBUG(0,("%s: EOF on stdin - terminating\n", binary_name));
 #if HAVE_GETPGRP
                if (getpgrp() == getpid()) {
+                       DEBUG(0,("Sending SIGTERM from pid %d\n", (int)getpid()));
                        kill(-getpgrp(), SIGTERM);
                }
 #endif
@@ -176,6 +180,18 @@ _NORETURN_ static void max_runtime_handler(struct tevent_context *ev,
        exit(0);
 }
 
+/*
+  pre-open the sam ldb to ensure the schema has been loaded. This
+  saves a lot of time in child processes  
+ */
+static void prime_samdb_schema(struct tevent_context *event_ctx)
+{
+       TALLOC_CTX *samdb_context;
+       samdb_context = talloc_new(event_ctx);
+       samdb_connect(samdb_context, event_ctx, cmdline_lp_ctx, system_session(samdb_context, cmdline_lp_ctx));
+       talloc_free(samdb_context);
+}
+
 /*
  main server.
 */
@@ -344,6 +360,8 @@ static int binary_smbd_main(const char *binary_name, int argc, const char *argv[
                                 discard_const(binary_name));
        }
 
+       prime_samdb_schema(event_ctx);
+
        DEBUG(0,("%s: using '%s' process model\n", binary_name, model));
        status = server_service_startup(event_ctx, cmdline_lp_ctx, model, 
                                        lp_server_services(cmdline_lp_ctx));