diff --git a/artiq/frontend/artiq_influxdb.py b/artiq/frontend/artiq_influxdb.py
index af93070c4..8c57b595e 100755
--- a/artiq/frontend/artiq_influxdb.py
+++ b/artiq/frontend/artiq_influxdb.py
@@ -52,8 +52,8 @@ def get_argparser():
         "--bind-port", default=3248, type=int,
         help="TCP port to listen to for control (default: %(default)d)")
     group.add_argument(
-        "--filter-file", default="influxdb_filter.pyon",
-        help="file to save the filter in (default: %(default)s)")
+        "--pattern-file", default="influxdb_patterns.pyon",
+        help="file to save the patterns in (default: %(default)s)")
     verbosity_args(parser)
     return parser
 
@@ -143,37 +143,57 @@ class MasterReader(TaskObject):
 
 
 class Filter:
-    def __init__(self, filter_file):
-        self.filter_file = filter_file
-        self.filter = []
+    def __init__(self, pattern_file):
+        self.pattern_file = pattern_file
+        self.patterns = []
         try:
-            self.filter = pyon.load_file(self.filter_file)
+            self.patterns = pyon.load_file(self.pattern_file)
         except FileNotFoundError:
-            logger.info("no filter file found, using empty filter")
+            logger.info("no pattern file found, logging everything")
 
     def _save(self):
-        pyon.store_file(self.filter_file, self.filter)
+        pyon.store_file(self.pattern_file, self.patterns)
 
+    # Privatize so that it is not shown in artiq_rpctool list-methods.
     def _filter(self, k):
-        for pattern in self.filter:
+        take = "+"
+        for pattern in self.patterns:
+            sign = "-"
+            if pattern[0] in "+-":
+                sign, pattern = pattern[0], pattern[1:]
             if fnmatch.fnmatchcase(k, pattern):
-                return False
-        return True
+                take = sign
+        return take == "+"
 
-    def add_pattern(self, pattern):
-        """Add a name pattern to ignore."""
-        if pattern not in self.filter:
-            self.filter.append(pattern)
+    def add_pattern(self, pattern, index=None):
+        """Add a pattern.
+
+        Optional + and - pattern prefixes specify whether to ignore or log
+        keys matching the rest of the pattern.
+        Default (in the absence of prefix) is to ignore. Keys that match no
+        pattern are logged. Last matched pattern takes precedence.
+
+        The optional index parameter specifies where to insert the pattern.
+        By default, patterns are added at the end. If index is an integer, it
+        specifies the index where the pattern is inserted. If it is a string,
+        that string must match an existing pattern and the new pattern is
+        inserted immediately after it."""
+        if pattern not in self.patterns:
+            if index is None:
+                index = len(self.patterns)
+            if isinstance(index, str):
+                index = self.patterns.index(index) + 1
+            self.patterns.insert(index, pattern)
         self._save()
 
     def remove_pattern(self, pattern):
-        """Remove a pattern name to ignore."""
-        self.pattern.remove(pattern)
+        """Remove a pattern."""
+        self.patterns.remove(pattern)
         self._save()
 
     def get_patterns(self):
-        """Show ignore patterns."""
-        return self.filter
+        """Show existing patterns."""
+        return self.patterns
 
 
 def main():
@@ -189,7 +209,7 @@ def main():
     writer.start()
     atexit.register(lambda: loop.run_until_complete(writer.stop()))
 
-    filter = Filter(args.filter_file)
+    filter = Filter(args.pattern_file)
     rpc_server = Server({"influxdb_filter": filter}, builtin_terminate=True)
     loop.run_until_complete(rpc_server.start(args.bind, args.bind_port))
     atexit.register(lambda: loop.run_until_complete(rpc_server.stop()))