Merge branch 'develop' of github.com:matrix-org/synapse into anoa/user_param_ui_auth github/anoa/user_param_ui_auth anoa/user_param_ui_auth

* 'develop' of github.com:matrix-org/synapse: (369 commits)
  Add functions to `MultiWriterIdGen` used by events stream (#8164)
  Do not allow send_nonmember_event to be called with shadow-banned users. (#8158)
  Changelog fixes
  1.19.1rc1
  Make StreamIdGen `get_next` and `get_next_mult` async  (#8161)
  Wording fixes to 'name' user admin api filter (#8163)
  Fix missing double-backtick in RST document
  Search in columns 'name' and 'displayname' in the admin users endpoint (#7377)
  Add type hints for state. (#8140)
  Stop shadow-banned users from sending non-member events. (#8142)
  Allow capping a room's retention policy (#8104)
  Add healthcheck for default localhost 8008 port on /health endpoint. (#8147)
  Fix flaky shadow-ban tests. (#8152)
  Fix join ratelimiter breaking profile updates and idempotency (#8153)
  Do not apply ratelimiting on joins to appservices (#8139)
  Don't fail /submit_token requests on incorrect session ID if request_token_inhibit_3pid_errors is turned on (#7991)
  Do not apply ratelimiting on joins to appservices (#8139)
  Micro-optimisations to get_auth_chain_ids (#8132)
  Allow denying or shadow banning registrations via the spam checker (#8034)
  Stop shadow-banned users from sending invites. (#8095)
  ...

3 files changed, 67 insertions, 14 deletions

diff --git a/debian/changelog b/debian/changelog

index 182a50ee37..bdaf59e9b9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,55 @@
+matrix-synapse-py3 (1.19.0) stable; urgency=medium
+
+  [ Synapse Packaging team ]
+  * New synapse release 1.19.0.
+
+  [ Aaron Raimist ]
+  * Fix outdated documentation for SYNAPSE_CACHE_FACTOR
+
+ -- Synapse Packaging team <packages@matrix.org>  Mon, 17 Aug 2020 14:06:42 +0100
+
+matrix-synapse-py3 (1.18.0) stable; urgency=medium
+
+  * New synapse release 1.18.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Thu, 30 Jul 2020 10:55:53 +0100
+
+matrix-synapse-py3 (1.17.0) stable; urgency=medium
+
+  * New synapse release 1.17.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Mon, 13 Jul 2020 10:20:31 +0100
+
+matrix-synapse-py3 (1.16.1) stable; urgency=medium
+
+  * New synapse release 1.16.1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Fri, 10 Jul 2020 12:09:24 +0100
+
+matrix-synapse-py3 (1.17.0rc1) stable; urgency=medium
+
+  * New synapse release 1.17.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Thu, 09 Jul 2020 16:53:12 +0100
+
+matrix-synapse-py3 (1.16.0) stable; urgency=medium
+
+  * New synapse release 1.16.0.
+
+ -- Synapse Packaging team <packages@matrix.org>  Wed, 08 Jul 2020 11:03:48 +0100
+
+matrix-synapse-py3 (1.15.2) stable; urgency=medium
+
+  * New synapse release 1.15.2.
+
+ -- Synapse Packaging team <packages@matrix.org>  Thu, 02 Jul 2020 10:34:00 -0400
+
+matrix-synapse-py3 (1.15.1) stable; urgency=medium
+
+  * New synapse release 1.15.1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 16 Jun 2020 10:27:50 +0100
+
 matrix-synapse-py3 (1.15.0) stable; urgency=medium
 
   * New synapse release 1.15.0.
diff --git a/debian/matrix-synapse.default b/debian/matrix-synapse.default

index 65dc2f33d8..f402d73bbf 100644
--- a/debian/matrix-synapse.default
+++ b/debian/matrix-synapse.default
@@ -1,2 +1,2 @@
 # Specify environment variables used when running Synapse
-# SYNAPSE_CACHE_FACTOR=1 (default)
+# SYNAPSE_CACHE_FACTOR=0.5 (default)
diff --git a/debian/synctl.ronn b/debian/synctl.ronn

index a73c832f62..1bad6094f3 100644
--- a/debian/synctl.ronn
+++ b/debian/synctl.ronn
@@ -46,19 +46,20 @@ Configuration file may be generated as follows:
 ## ENVIRONMENT
 
   * `SYNAPSE_CACHE_FACTOR`:
-    Synapse's architecture is quite RAM hungry currently - a lot of
-    recent room data and metadata is deliberately cached in RAM in
-    order to speed up common requests.  This will be improved in
-    future, but for now the easiest way to either reduce the RAM usage
-    (at the risk of slowing things down) is to set the
-    SYNAPSE_CACHE_FACTOR environment variable. Roughly speaking, a
-    SYNAPSE_CACHE_FACTOR of 1.0 will max out at around 3-4GB of
-    resident memory - this is what we currently run the matrix.org
-    on. The default setting is currently 0.1, which is probably around
-    a ~700MB footprint. You can dial it down further to 0.02 if
-    desired, which targets roughly ~512MB. Conversely you can dial it
-    up if you need performance for lots of users and have a box with a
-    lot of RAM.
+    Synapse's architecture is quite RAM hungry currently - we deliberately
+    cache a lot of recent room data and metadata in RAM in order to speed up
+    common requests. We'll improve this in the future, but for now the easiest
+    way to either reduce the RAM usage (at the risk of slowing things down)
+    is to set the almost-undocumented ``SYNAPSE_CACHE_FACTOR`` environment
+    variable. The default is 0.5, which can be decreased to reduce RAM usage
+    in memory constrained enviroments, or increased if performance starts to
+    degrade.
+
+    However, degraded performance due to a low cache factor, common on
+    machines with slow disks, often leads to explosions in memory use due
+    backlogged requests. In this case, reducing the cache factor will make
+    things worse. Instead, try increasing it drastically. 2.0 is a good
+    starting value.
 
 ## COPYRIGHT