Merge pull request #83 from matrix-org/nofile_limit_config

Add config option to set the soft fd limit on start

synapse/app/homeserver.py

@@ -53,6 +53,7 @@ import synapse
 import logging
 import os
 import re
+import resource
 import subprocess
 import sqlite3
 import syweb
@@ -146,8 +147,8 @@ class SynapseHomeServer(HomeServer):
         # instead, we'll store a copy of this mapping so we can actually add
         # extra resources to existing nodes. See self._resource_id for the key.
         resource_mappings = {}
-        for (full_path, resource) in desired_tree:
+        for full_path, res in desired_tree:
-            logger.info("Attaching %s to path %s", resource, full_path)
+            logger.info("Attaching %s to path %s", res, full_path)
             last_resource = self.root_resource
             for path_seg in full_path.split('/')[1:-1]:
                 if path_seg not in last_resource.listNames():
@@ -178,12 +179,12 @@ class SynapseHomeServer(HomeServer):
                                                      child_name)
                     child_resource = resource_mappings[child_res_id]
                     # steal the children
-                    resource.putChild(child_name, child_resource)
+                    res.putChild(child_name, child_resource)
 
             # finally, insert the desired resource in the right place
-            last_resource.putChild(last_path_seg, resource)
+            last_resource.putChild(last_path_seg, res)
             res_id = self._resource_id(last_resource, last_path_seg)
-            resource_mappings[res_id] = resource
+            resource_mappings[res_id] = res
 
         return self.root_resource
 
@@ -275,6 +276,20 @@ def get_version_string():
     return ("Synapse/%s" % (synapse.__version__,)).encode("ascii")
 
 
+def change_resource_limit(soft_file_no):
+    try:
+        soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
+
+        if not soft_file_no:
+            soft_file_no = hard
+
+        resource.setrlimit(resource.RLIMIT_NOFILE, (soft_file_no, hard))
+
+        logger.info("Set file limit to: %d", soft_file_no)
+    except (ValueError, resource.error) as e:
+        logger.warn("Failed to set file limit: %s", e)
+
+
 def setup():
     config = HomeServerConfig.load_config(
         "Synapse Homeserver",
@@ -351,10 +366,11 @@ def setup():
 
     if config.daemonize:
         print config.pid_file
+
         daemon = Daemonize(
             app="synapse-homeserver",
             pid=config.pid_file,
-            action=run,
+            action=lambda: run(config),
             auto_close_fds=False,
             verbose=True,
             logger=logger,
@@ -362,11 +378,13 @@ def setup():
 
         daemon.start()
     else:
-        reactor.run()
+        run(config)
 
 
-def run():
+def run(config):
     with LoggingContext("run"):
+        change_resource_limit(config.soft_file_limit)
+
         reactor.run()
 
 

synapse/config/server.py

@@ -31,6 +31,7 @@ class ServerConfig(Config):
         self.webclient = True
         self.manhole = args.manhole
         self.no_tls = args.no_tls
+        self.soft_file_limit = args.soft_file_limit
 
         if not args.content_addr:
             host = args.server_name
@@ -77,6 +78,12 @@ class ServerConfig(Config):
                                   "content repository")
         server_group.add_argument("--no-tls", action='store_true',
                                   help="Don't bind to the https port.")
+        server_group.add_argument("--soft-file-limit", type=int, default=0,
+                                  help="Set the soft limit on the number of "
+                                       "file descriptors synapse can use. "
+                                       "Zero is used to indicate synapse "
+                                       "should set the soft limit to the hard"
+                                       "limit.")
 
     def read_signing_key(self, signing_key_path):
         signing_keys = self.read_file(signing_key_path, "signing_key")