diff --git a/docker/Dockerfile b/docker/Dockerfile
index db44c02a92..95776f0583 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,21 +1,26 @@
-ARG PYTHON_VERSION=2
+ARG PYTHON_VERSION=3
 
 ###
 ### Stage 0: builder
 ###
-FROM docker.io/python:${PYTHON_VERSION}-alpine3.8 as builder
+FROM docker.io/python:${PYTHON_VERSION}-slim-stretch as builder
 
 # install the OS build deps
 
-RUN apk add \
-        build-base \
+RUN apt-get update && apt-get install -y \
+        build-essential \
         libffi-dev \
-        libjpeg-turbo-dev \
-        libressl-dev \
-        libxslt-dev \
-        linux-headers \
-        postgresql-dev \
-        zlib-dev
+        sqlite3 \
+        libssl-dev \
+        libjpeg-dev \
+        libxslt1-dev \
+        libxml2-dev \
+        libpq-dev
+
+# for ksm_preload
+RUN apt-get install -y \
+        git \
+        cmake
 
 # build things which have slow build steps, before we copy synapse, so that
 # the layer can be cached.
@@ -34,23 +39,40 @@ RUN pip install --prefix="/install" --no-warn-script-location \
 COPY . /synapse
 RUN pip install --prefix="/install" --no-warn-script-location \
         lxml \
-        psycopg2 \
+        psycopg2-binary \
         /synapse
 
+# N.B. to work, this needs:
+# echo 1 > /sys/kernel/mm/ksm/run
+# echo 31250 > /sys/kernel/mm/ksm/pages_to_scan # 128MB of 4KB pages at a time
+# echo 10000 > /sys/kernel/mm/ksm/pages_to_scan # 40MB of pages at a time
+# ...to be run in the Docker host
+
+RUN git clone https://github.com/unbrice/ksm_preload && \
+    cd ksm_preload && \
+    cmake . && \
+    make && \
+    cp libksm_preload.so /install/lib
+
 ###
 ### Stage 1: runtime
 ###
 
-FROM docker.io/python:${PYTHON_VERSION}-alpine3.8
+FROM docker.io/python:${PYTHON_VERSION}-slim-stretch
 
-RUN apk add --no-cache --virtual .runtime_deps \
-        libffi \
-        libjpeg-turbo \
-        libressl \
-        libxslt \
-        libpq \
-        zlib \
-        su-exec
+RUN apt-get update && apt-get install -y \
+    procps \
+    net-tools \
+    iproute2 \
+    tcpdump \
+    traceroute \
+    mtr-tiny \
+    inetutils-ping \
+    less \
+    lsof
+
+# for topologiser
+RUN pip install flask
 
 COPY --from=builder /install /usr/local
 COPY ./docker/start.py /start.py
@@ -58,6 +80,11 @@ COPY ./docker/conf /conf
 
 VOLUME ["/data"]
 
-EXPOSE 8008/tcp 8448/tcp
+EXPOSE 8008/tcp 8448/tcp 3000/tcp
+
+ENV LD_PRELOAD=/usr/local/lib/libksm_preload.so
+
+# default is 32768 (8 4KB pages)
+ENV KSMP_MERGE_THRESHOLD=16384
 
 ENTRYPOINT ["/start.py"]
diff --git a/docker/conf/homeserver.yaml b/docker/conf/homeserver.yaml
index 1b0f655d26..4194e843c0 100644
--- a/docker/conf/homeserver.yaml
+++ b/docker/conf/homeserver.yaml
@@ -55,7 +55,7 @@ database:
     database: "{{ POSTGRES_DB or "synapse" }}"
     host: "{{ POSTGRES_HOST or "db" }}"
     port: "{{ POSTGRES_PORT or "5432" }}"
-    cp_min: 5
+    cp_min: 1
     cp_max: 10
 {% else %}
 database:
diff --git a/docker/start.py b/docker/start.py
index 346df8c87f..01cccaf08e 100755
--- a/docker/start.py
+++ b/docker/start.py
@@ -6,6 +6,7 @@ import sys
 import subprocess
 import glob
 import codecs
+import time
 
 # Utility functions
 convert = lambda src, dst, environ: open(dst, "w").write(jinja2.Template(open(src).read()).render(**environ))
@@ -31,6 +32,10 @@ def generate_secrets(environ, secrets):
 # Prepare the configuration
 mode = sys.argv[1] if len(sys.argv) > 1 else None
 environ = os.environ.copy()
+
+for e in environ:
+    print("%s:%s" % (e, environ[e]))
+
 ownership = "{}:{}".format(environ.get("UID", 991), environ.get("GID", 991))
 args = ["python", "-m", "synapse.app.homeserver"]
 
@@ -64,4 +69,8 @@ else:
         args += ["--config-path", "/compiled/homeserver.yaml"]
     # Generate missing keys and start synapse
     subprocess.check_output(args + ["--generate-keys"])
-    os.execv("/sbin/su-exec", ["su-exec", ownership] + args)
+
+    os.system("(sleep 5; /usr/local/bin/register_new_matrix_user -u matthew -p isildur -c /compiled/homeserver.yaml -a) &");
+
+    os.execv("/usr/local/bin/python", args)
+
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 2f5f8819c1..39e4bd2b11 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -38,7 +38,7 @@ def check(event, auth_events, do_sig_check=True, do_size_check=True):
         AuthError if the checks fail
 
     Returns:
-         if the auth checks pass.
+        if the auth checks pass.
     """
     if do_size_check:
         _check_size_limits(event)
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index ba3856674d..172b6947d4 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -347,7 +347,7 @@ class PresenceHandler(object):
         """Checks the presence of users that have timed out and updates as
         appropriate.
         """
-        logger.info("Handling presence timeouts")
+        #logger.info("Handling presence timeouts")
         now = self.clock.time_msec()
 
         try:
diff --git a/synapse/handlers/typing.py b/synapse/handlers/typing.py
index a61bbf9392..2af164a142 100644
--- a/synapse/handlers/typing.py
+++ b/synapse/handlers/typing.py
@@ -86,7 +86,7 @@ class TypingHandler(object):
         self._room_typing = {}
 
     def _handle_timeouts(self):
-        logger.info("Checking for typing timeouts")
+        #logger.info("Checking for typing timeouts")
 
         now = self.clock.time_msec()