diff --git a/html/inc/submit_util.inc b/html/inc/submit_util.inc
index 12e7181217..3daebe8ba2 100644
--- a/html/inc/submit_util.inc
+++ b/html/inc/submit_util.inc
@@ -21,22 +21,26 @@
 
 require_once("../inc/submit_db.inc");
 
-$log_file = null;
-$verbose = true;
-
+// write status and error messages to log
+//
 function log_write($x) {
-    global $verbose, $log_file;
+    static $enabled, $log_file;
 
-    if (!$verbose) return;
-    if (!$log_file) {
-        $hostname = gethostname();
-        $log_dir = "../../log_$hostname";
-        if (!file_exists($log_dir)) {
-            mkdir($log_dir);
+    if (!isset($enabled)) {
+        $enabled = false;
+        $filename = parse_config(get_config(), "<remote_submit_log>");
+        if (!$filename) {
+            return;
         }
-        $log_file = fopen("$log_dir/submit_log.txt", "a");
+        $log_dir = parse_config(get_config(), "<log_dir>");
+        if (!$log_dir) {
+            return;
+        }
+        $log_file = fopen("$log_dir/$filename", "a");
         if (!$log_file) return;
+        $enabled = true;
     }
+    if (!$enabled) return;
     fwrite($log_file, sprintf("%s: %s\n", strftime("%c"), $x));
     fflush($log_file);
 }
diff --git a/html/user/submit_rpc_handler.php b/html/user/submit_rpc_handler.php
index e59445c847..845aa6dbd8 100644
--- a/html/user/submit_rpc_handler.php
+++ b/html/user/submit_rpc_handler.php
@@ -471,6 +471,7 @@ function submit_batch($r) {
             log_write("batch update to njobs failed");
             xml_error(-1, "batch->update() failed");
         }
+        log_write("adding jobs to existing batch $batch_id");
     } else {
         $batch_name = (string)($r->batch->batch_name);
         $batch_name = BoincDb::escape_string($batch_name);
@@ -511,6 +512,7 @@ function submit_batch($r) {
         log_write("batch update to IN_PROGRESS failed");
         xml_error(-1, "batch->update() failed");
     }
+    log_write("updated batch state to IN_PROGRESS");
 
     echo "<batch_id>$batch_id</batch_id>
         </submit_batch>
@@ -1022,13 +1024,13 @@ estimate_batch($r);
 exit;
 }
 
-$request_log = parse_config(get_config(), "<remote_submission_log>");
+// optionally write request message (XML) to log file
+//
+$request_log = parse_config(get_config(), "<remote_submit_request_log>");
 if ($request_log) {
-    $request_log_dir = parse_config(get_config(), "<log_dir>");
-    if ($request_log_dir) {
-        $request_log = $request_log_dir . "/" . $request_log;
-    }
-    if ($file = fopen($request_log, "a+")) {
+    $log_dir = parse_config(get_config(), "<log_dir>");
+    $request_log = $log_dir . "/" . $request_log;
+    if ($file = fopen($request_log, "a")) {
         fwrite($file, "\n<submit_rpc_handler date=\"" . date(DATE_ATOM) . "\">\n" . $_POST['request'] . "\n</submit_rpc_handler>\n");
         fclose($file);
     }
diff --git a/tools/submit_api_test.py b/tools/submit_api_test.py
index 63e5e39099..db1751392f 100644
--- a/tools/submit_api_test.py
+++ b/tools/submit_api_test.py
@@ -191,5 +191,5 @@ def test_get_output_files():
     print(r)
 
 #test_query_batch(328)
-test_submit_batch('batch_41')
+test_submit_batch('batch_43')
 #test_create_batch('batch_33')