mirrors/synapse
1
0
Fork 0
mirror of https://github.com/element-hq/synapse.git synced 2024-12-19 17:56:19 +03:00
Code Issues Projects Releases Packages Wiki Activity

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

Browse source
This commit is contained in:
Erik Johnston 2017-03-21 13:09:38 +00:00
commit 5bf6bcb850
19 changed files with 929 additions and 164 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

447
docs/log_contexts.rst
View file

@ -1,10 +1,441 @@
What do I do about "Unexpected logging context" debug log-lines everywhere?
Log contexts
============
<Mjark> The logging context lives in thread local storage
<Mjark> Sometimes it gets out of sync with what it should actually be, usually because something scheduled something to run on the reactor without preserving the logging context.
<Matthew> what is the impact of it getting out of sync? and how and when should we preserve log context?
<Mjark> The impact is that some of the CPU and database metrics will be under-reported, and some log lines will be mis-attributed.
<Mjark> It should happen auto-magically in all the APIs that do IO or otherwise defer to the reactor.
<Erik> Mjark: the other place is if we branch, e.g. using defer.gatherResults
.. contents::
Unanswered: how and when should we preserve log context?
To help track the processing of individual requests, synapse uses a
'log context' to track which request it is handling at any given moment. This
is done via a thread-local variable; a ``logging.Filter`` is then used to fish
the information back out of the thread-local variable and add it to each log
record.
Logcontexts are also used for CPU and database accounting, so that we can track
which requests were responsible for high CPU use or database activity.
The ``synapse.util.logcontext`` module provides a facilities for managing the
current log context (as well as providing the ``LoggingContextFilter`` class).
Deferreds make the whole thing complicated, so this document describes how it
all works, and how to write code which follows the rules.
Logcontexts without Deferreds
-----------------------------
In the absence of any Deferred voodoo, things are simple enough. As with any
code of this nature, the rule is that our function should leave things as it
found them:
.. code:: python
from synapse.util import logcontext # omitted from future snippets
def handle_request(request_id):
request_context = logcontext.LoggingContext()
calling_context = logcontext.LoggingContext.current_context()
logcontext.LoggingContext.set_current_context(request_context)
try:
request_context.request = request_id
do_request_handling()
logger.debug("finished")
finally:
logcontext.LoggingContext.set_current_context(calling_context)
def do_request_handling():
logger.debug("phew") # this will be logged against request_id
LoggingContext implements the context management methods, so the above can be
written much more succinctly as:
.. code:: python
def handle_request(request_id):
with logcontext.LoggingContext() as request_context:
request_context.request = request_id
do_request_handling()
logger.debug("finished")
def do_request_handling():
logger.debug("phew")
Using logcontexts with Deferreds
--------------------------------
Deferreds — and in particular, ``defer.inlineCallbacks`` — break
the linear flow of code so that there is no longer a single entry point where
we should set the logcontext and a single exit point where we should remove it.
Consider the example above, where ``do_request_handling`` needs to do some
blocking operation, and returns a deferred:
.. code:: python
@defer.inlineCallbacks
def handle_request(request_id):
with logcontext.LoggingContext() as request_context:
request_context.request = request_id
yield do_request_handling()
logger.debug("finished")
In the above flow:
* The logcontext is set
* ``do_request_handling`` is called, and returns a deferred
* ``handle_request`` yields the deferred
* The ``inlineCallbacks`` wrapper of ``handle_request`` returns a deferred
So we have stopped processing the request (and will probably go on to start
processing the next), without clearing the logcontext.
To circumvent this problem, synapse code assumes that, wherever you have a
deferred, you will want to yield on it. To that end, whereever functions return
a deferred, we adopt the following conventions:
**Rules for functions returning deferreds:**
* If the deferred is already complete, the function returns with the same
logcontext it started with.
* If the deferred is incomplete, the function clears the logcontext before
returning; when the deferred completes, it restores the logcontext before
running any callbacks.
That sounds complicated, but actually it means a lot of code (including the
example above) "just works". There are two cases:
* If ``do_request_handling`` returns a completed deferred, then the logcontext
will still be in place. In this case, execution will continue immediately
after the ``yield``; the "finished" line will be logged against the right
context, and the ``with`` block restores the original context before we
return to the caller.
* If the returned deferred is incomplete, ``do_request_handling`` clears the
logcontext before returning. The logcontext is therefore clear when
``handle_request`` yields the deferred. At that point, the ``inlineCallbacks``
wrapper adds a callback to the deferred, and returns another (incomplete)
deferred to the caller, and it is safe to begin processing the next request.
Once ``do_request_handling``'s deferred completes, it will reinstate the
logcontext, before running the callback added by the ``inlineCallbacks``
wrapper. That callback runs the second half of ``handle_request``, so again
the "finished" line will be logged against the right
context, and the ``with`` block restores the original context.
As an aside, it's worth noting that ``handle_request`` follows our rules -
though that only matters if the caller has its own logcontext which it cares
about.
The following sections describe pitfalls and helpful patterns when implementing
these rules.
Always yield your deferreds
---------------------------
Whenever you get a deferred back from a function, you should ``yield`` on it
as soon as possible. (Returning it directly to your caller is ok too, if you're
not doing ``inlineCallbacks``.) Do not pass go; do not do any logging; do not
call any other functions.
.. code:: python
@defer.inlineCallbacks
def fun():
logger.debug("starting")
yield do_some_stuff() # just like this
d = more_stuff()
result = yield d # also fine, of course
defer.returnValue(result)
def nonInlineCallbacksFun():
logger.debug("just a wrapper really")
return do_some_stuff() # this is ok too - the caller will yield on
# it anyway.
Provided this pattern is followed all the way back up to the callchain to where
the logcontext was set, this will make things work out ok: provided
``do_some_stuff`` and ``more_stuff`` follow the rules above, then so will
``fun`` (as wrapped by ``inlineCallbacks``) and ``nonInlineCallbacksFun``.
It's all too easy to forget to ``yield``: for instance if we forgot that
``do_some_stuff`` returned a deferred, we might plough on regardless. This
leads to a mess; it will probably work itself out eventually, but not before
a load of stuff has been logged against the wrong content. (Normally, other
things will break, more obviously, if you forget to ``yield``, so this tends
not to be a major problem in practice.)
Of course sometimes you need to do something a bit fancier with your Deferreds
- not all code follows the linear A-then-B-then-C pattern. Notes on
implementing more complex patterns are in later sections.
Where you create a new Deferred, make it follow the rules
---------------------------------------------------------
Most of the time, a Deferred comes from another synapse function. Sometimes,
though, we need to make up a new Deferred, or we get a Deferred back from
external code. We need to make it follow our rules.
The easy way to do it is with a combination of ``defer.inlineCallbacks``, and
``logcontext.PreserveLoggingContext``. Suppose we want to implement ``sleep``,
which returns a deferred which will run its callbacks after a given number of
seconds. That might look like:
.. code:: python
# not a logcontext-rules-compliant function
def get_sleep_deferred(seconds):
d = defer.Deferred()
reactor.callLater(seconds, d.callback, None)
return d
That doesn't follow the rules, but we can fix it by wrapping it with
``PreserveLoggingContext`` and ``yield`` ing on it:
.. code:: python
@defer.inlineCallbacks
def sleep(seconds):
with PreserveLoggingContext():
yield get_sleep_deferred(seconds)
This technique works equally for external functions which return deferreds,
or deferreds we have made ourselves.
XXX: think this is what ``preserve_context_over_deferred`` is supposed to do,
though it is broken, in that it only restores the logcontext for the duration
of the callbacks, which doesn't comply with the logcontext rules.
Fire-and-forget
---------------
Sometimes you want to fire off a chain of execution, but not wait for its
result. That might look a bit like this:
.. code:: python
@defer.inlineCallbacks
def do_request_handling():
yield foreground_operation()
# *don't* do this
background_operation()
logger.debug("Request handling complete")
@defer.inlineCallbacks
def background_operation():
yield first_background_step()
logger.debug("Completed first step")
yield second_background_step()
logger.debug("Completed second step")
The above code does a couple of steps in the background after
``do_request_handling`` has finished. The log lines are still logged against
the ``request_context`` logcontext, which may or may not be desirable. There
are two big problems with the above, however. The first problem is that, if
``background_operation`` returns an incomplete Deferred, it will expect its
caller to ``yield`` immediately, so will have cleared the logcontext. In this
example, that means that 'Request handling complete' will be logged without any
context.
The second problem, which is potentially even worse, is that when the Deferred
returned by ``background_operation`` completes, it will restore the original
logcontext. There is nothing waiting on that Deferred, so the logcontext will
leak into the reactor and possibly get attached to some arbitrary future
operation.
There are two potential solutions to this.
One option is to surround the call to ``background_operation`` with a
``PreserveLoggingContext`` call. That will reset the logcontext before
starting ``background_operation`` (so the context restored when the deferred
completes will be the empty logcontext), and will restore the current
logcontext before continuing the foreground process:
.. code:: python
@defer.inlineCallbacks
def do_request_handling():
yield foreground_operation()
# start background_operation off in the empty logcontext, to
# avoid leaking the current context into the reactor.
with PreserveLoggingContext():
background_operation()
# this will now be logged against the request context
logger.debug("Request handling complete")
Obviously that option means that the operations done in
``background_operation`` would be not be logged against a logcontext (though
that might be fixed by setting a different logcontext via a ``with
LoggingContext(...)`` in ``background_operation``).
The second option is to use ``logcontext.preserve_fn``, which wraps a function
so that it doesn't reset the logcontext even when it returns an incomplete
deferred, and adds a callback to the returned deferred to reset the
logcontext. In other words, it turns a function that follows the Synapse rules
about logcontexts and Deferreds into one which behaves more like an external
function — the opposite operation to that described in the previous section.
It can be used like this:
.. code:: python
@defer.inlineCallbacks
def do_request_handling():
yield foreground_operation()
logcontext.preserve_fn(background_operation)()
# this will now be logged against the request context
logger.debug("Request handling complete")
XXX: I think ``preserve_context_over_fn`` is supposed to do the first option,
but the fact that it does ``preserve_context_over_deferred`` on its results
means that its use is fraught with difficulty.
Passing synapse deferreds into third-party functions
----------------------------------------------------
A typical example of this is where we want to collect together two or more
deferred via ``defer.gatherResults``:
.. code:: python
d1 = operation1()
d2 = operation2()
d3 = defer.gatherResults([d1, d2])
This is really a variation of the fire-and-forget problem above, in that we are
firing off ``d1`` and ``d2`` without yielding on them. The difference
is that we now have third-party code attached to their callbacks. Anyway either
technique given in the `Fire-and-forget`_ section will work.
Of course, the new Deferred returned by ``gatherResults`` needs to be wrapped
in order to make it follow the logcontext rules before we can yield it, as
described in `Where you create a new Deferred, make it follow the rules`_.
So, option one: reset the logcontext before starting the operations to be
gathered:
.. code:: python
@defer.inlineCallbacks
def do_request_handling():
with PreserveLoggingContext():
d1 = operation1()
d2 = operation2()
result = yield defer.gatherResults([d1, d2])
In this case particularly, though, option two, of using
``logcontext.preserve_fn`` almost certainly makes more sense, so that
``operation1`` and ``operation2`` are both logged against the original
logcontext. This looks like:
.. code:: python
@defer.inlineCallbacks
def do_request_handling():
d1 = logcontext.preserve_fn(operation1)()
d2 = logcontext.preserve_fn(operation2)()
with PreserveLoggingContext():
result = yield defer.gatherResults([d1, d2])
Was all this really necessary?
------------------------------
The conventions used work fine for a linear flow where everything happens in
series via ``defer.inlineCallbacks`` and ``yield``, but are certainly tricky to
follow for any more exotic flows. It's hard not to wonder if we could have done
something else.
We're not going to rewrite Synapse now, so the following is entirely of
academic interest, but I'd like to record some thoughts on an alternative
approach.
I briefly prototyped some code following an alternative set of rules. I think
it would work, but I certainly didn't get as far as thinking how it would
interact with concepts as complicated as the cache descriptors.
My alternative rules were:
* functions always preserve the logcontext of their caller, whether or not they
are returning a Deferred.
* Deferreds returned by synapse functions run their callbacks in the same
context as the function was orignally called in.
The main point of this scheme is that everywhere that sets the logcontext is
responsible for clearing it before returning control to the reactor.
So, for example, if you were the function which started a ``with
LoggingContext`` block, you wouldn't ``yield`` within it — instead you'd start
off the background process, and then leave the ``with`` block to wait for it:
.. code:: python
def handle_request(request_id):
with logcontext.LoggingContext() as request_context:
request_context.request = request_id
d = do_request_handling()
def cb(r):
logger.debug("finished")
d.addCallback(cb)
return d
(in general, mixing ``with LoggingContext`` blocks and
``defer.inlineCallbacks`` in the same function leads to slighly
counter-intuitive code, under this scheme).
Because we leave the original ``with`` block as soon as the Deferred is
returned (as opposed to waiting for it to be resolved, as we do today), the
logcontext is cleared before control passes back to the reactor; so if there is
some code within ``do_request_handling`` which needs to wait for a Deferred to
complete, there is no need for it to worry about clearing the logcontext before
doing so:
.. code:: python
def handle_request():
r = do_some_stuff()
r.addCallback(do_some_more_stuff)
return r
— and provided ``do_some_stuff`` follows the rules of returning a Deferred which
runs its callbacks in the original logcontext, all is happy.
The business of a Deferred which runs its callbacks in the original logcontext
isn't hard to achieve — we have it today, in the shape of
``logcontext._PreservingContextDeferred``:
.. code:: python
def do_some_stuff():
deferred = do_some_io()
pcd = _PreservingContextDeferred(LoggingContext.current_context())
deferred.chainDeferred(pcd)
return pcd
It turns out that, thanks to the way that Deferreds chain together, we
automatically get the property of a context-preserving deferred with
``defer.inlineCallbacks``, provided the final Defered the function ``yields``
on has that property. So we can just write:
.. code:: python
@defer.inlineCallbacks
def handle_request():
yield do_some_stuff()
yield do_some_more_stuff()
To conclude: I think this scheme would have worked equally well, with less
danger of messing it up, and probably made some more esoteric code easier to
write. But again — changing the conventions of the entire Synapse codebase is
not a sensible option for the marginal improvement offered.

8
synapse/app/appservice.py
View file

@ -29,7 +29,7 @@ from synapse.replication.slave.storage.registration import SlavedRegistrationSto
from synapse.storage.engines import create_engine
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -187,7 +187,11 @@ def start(config_options):
ps.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

8
synapse/app/client_reader.py
View file

@ -35,7 +35,7 @@ from synapse.storage.client_ips import ClientIpStore
from synapse.storage.engines import create_engine
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -193,7 +193,11 @@ def start(config_options):
ss.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

8
synapse/app/federation_reader.py
View file

@ -31,7 +31,7 @@ from synapse.server import HomeServer
from synapse.storage.engines import create_engine
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -184,7 +184,11 @@ def start(config_options):
ss.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

8
synapse/app/federation_sender.py
View file

@ -35,7 +35,7 @@ from synapse.storage.engines import create_engine
from synapse.storage.presence import UserPresenceState
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -193,7 +193,11 @@ def start(config_options):
ps.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

9
synapse/app/homeserver.py
View file

@ -52,7 +52,7 @@ from synapse.api.urls import (
)
from synapse.config.homeserver import HomeServerConfig
from synapse.crypto import context_factory
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.metrics import register_memory_metrics, get_metrics_for
from synapse.metrics.resource import MetricsResource, METRICS_PREFIX
from synapse.replication.resource import ReplicationResource, REPLICATION_PREFIX
@ -456,7 +456,12 @@ def run(hs):
def in_thread():
# Uncomment to enable tracing of log context changes.
# sys.settrace(logcontext_tracer)
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
change_resource_limit(hs.config.soft_file_limit)
if hs.config.gc_thresholds:
gc.set_threshold(*hs.config.gc_thresholds)

8
synapse/app/media_repository.py
View file

@ -32,7 +32,7 @@ from synapse.storage.engines import create_engine
from synapse.storage.media_repository import MediaRepositoryStore
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -190,7 +190,11 @@ def start(config_options):
ss.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

9
synapse/app/pusher.py
View file

@ -31,7 +31,8 @@ from synapse.storage.engines import create_engine
from synapse.storage import DataStore
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext, preserve_fn
from synapse.util.logcontext import LoggingContext, preserve_fn, \
PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
@ -275,7 +276,11 @@ def start(config_options):
ps.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

9
synapse/app/synchrotron.py
View file

@ -48,7 +48,8 @@ from synapse.storage.presence import PresenceStore, UserPresenceState
from synapse.storage.roommember import RoomMemberStore
from synapse.util.async import sleep
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext, preserve_fn
from synapse.util.logcontext import LoggingContext, preserve_fn, \
PreserveLoggingContext
from synapse.util.manhole import manhole
from synapse.util.rlimit import change_resource_limit
from synapse.util.stringutils import random_string
@ -496,7 +497,11 @@ def start(config_options):
ss.start_listening(config.worker_listeners)
def run():
with LoggingContext("run"):
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
change_resource_limit(config.soft_file_limit)
if config.gc_thresholds:

9
synapse/crypto/keyring.py
View file

@ -96,10 +96,11 @@ class Keyring(object):
verify_requests = []
for server_name, json_object in server_and_json:
logger.debug("Verifying for %s", server_name)
key_ids = signature_ids(json_object, server_name)
if not key_ids:
logger.warn("Request from %s: no supported signature keys",
server_name)
deferred = defer.fail(SynapseError(
400,
"Not signed with a supported algorithm",
@ -108,6 +109,9 @@ class Keyring(object):
else:
deferred = defer.Deferred()
logger.debug("Verifying for %s with key_ids %s",
server_name, key_ids)
verify_request = VerifyKeyRequest(
server_name, key_ids, json_object, deferred
)
@ -142,6 +146,9 @@ class Keyring(object):
json_object = verify_request.json_object
logger.debug("Got key %s %s:%s for server %s, verifying" % (
key_id, verify_key.alg, verify_key.version, server_name,
))
try:
verify_signed_json(json_object, server_name, verify_key)
except:

26
synapse/events/snapshot.py
View file

@ -15,6 +15,32 @@
class EventContext(object):
"""
Attributes:
current_state_ids (dict[(str, str), str]):
The current state map including the current event.
(type, state_key) -> event_id
prev_state_ids (dict[(str, str), str]):
The current state map excluding the current event.
(type, state_key) -> event_id
state_group (int): state group id
rejected (bool|str): A rejection reason if the event was rejected, else
False
push_actions (list[(str, list[object])]): list of (user_id, actions)
tuples
prev_group (int): Previously persisted state group. ``None`` for an
outlier.
delta_ids (dict[(str, str), str]): Delta from ``prev_group``.
(type, state_key) -> event_id. ``None`` for an outlier.
prev_state_events (?): XXX: is this ever set to anything other than
the empty list?
"""
__slots__ = [
"current_state_ids",
"prev_state_ids",

79
synapse/handlers/federation.py
View file

@ -14,6 +14,7 @@
# limitations under the License.
"""Contains handlers for federation events."""
import synapse.util.logcontext
from signedjson.key import decode_verify_key_bytes
from signedjson.sign import verify_signed_json
from unpaddedbase64 import decode_base64
@ -114,6 +115,14 @@ class FederationHandler(BaseHandler):
logger.debug("Already seen pdu %s", pdu.event_id)
return
# If we are currently in the process of joining this room, then we
# queue up events for later processing.
if pdu.room_id in self.room_queues:
logger.info("Ignoring PDU %s for room %s from %s for now; join "
"in progress", pdu.event_id, pdu.room_id, origin)
self.room_queues[pdu.room_id].append((pdu, origin))
return
state = None
auth_chain = []
@ -274,26 +283,13 @@ class FederationHandler(BaseHandler):
@log_function
@defer.inlineCallbacks
def _process_received_pdu(self, origin, pdu, state=None, auth_chain=None):
def _process_received_pdu(self, origin, pdu, state, auth_chain):
""" Called when we have a new pdu. We need to do auth checks and put it
through the StateHandler.
auth_chain and state are None if we already have the necessary state
and prev_events in the db
"""
event = pdu
logger.debug("Got event: %s", event.event_id)
# If we are currently in the process of joining this room, then we
# queue up events for later processing.
if event.room_id in self.room_queues:
self.room_queues[event.room_id].append((pdu, origin))
return
logger.debug("Processing event: %s", event.event_id)
logger.debug("Event: %s", event)
logger.debug("Processing event: %s", event)
# FIXME (erikj): Awful hack to make the case where we are not currently
# in the room work
@ -862,8 +858,6 @@ class FederationHandler(BaseHandler):
"""
logger.debug("Joining %s to %s", joinee, room_id)
yield self.store.clean_room_for_join(room_id)
origin, event = yield self._make_and_verify_event(
target_hosts,
room_id,
@ -872,7 +866,15 @@ class FederationHandler(BaseHandler):
content,
)
# This shouldn't happen, because the RoomMemberHandler has a
# linearizer lock which only allows one operation per user per room
# at a time - so this is just paranoia.
assert (room_id not in self.room_queues)
self.room_queues[room_id] = []
yield self.store.clean_room_for_join(room_id)
handled_events = set()
try:
@ -925,17 +927,36 @@ class FederationHandler(BaseHandler):
room_queue = self.room_queues[room_id]
del self.room_queues[room_id]
for p, origin in room_queue:
if p.event_id in handled_events:
continue
# we don't need to wait for the queued events to be processed -
# it's just a best-effort thing at this point. We do want to do
# them roughly in order, though, otherwise we'll end up making
# lots of requests for missing prev_events which we do actually
# have. Hence we fire off the deferred, but don't wait for it.
try:
self._process_received_pdu(origin, p)
except:
logger.exception("Couldn't handle pdu")
synapse.util.logcontext.preserve_fn(self._handle_queued_pdus)(
room_queue
)
defer.returnValue(True)
@defer.inlineCallbacks
def _handle_queued_pdus(self, room_queue):
"""Process PDUs which got queued up while we were busy send_joining.
Args:
room_queue (list[FrozenEvent, str]): list of PDUs to be processed
and the servers that sent them
"""
for p, origin in room_queue:
try:
logger.info("Processing queued PDU %s which was received "
"while we were joining %s", p.event_id, p.room_id)
yield self.on_receive_pdu(origin, p)
except Exception as e:
logger.warn(
"Error handling queued PDU %s from %s: %s",
p.event_id, origin, e)
@defer.inlineCallbacks
@log_function
def on_make_join_request(self, room_id, user_id):
@ -1517,7 +1538,17 @@ class FederationHandler(BaseHandler):
@defer.inlineCallbacks
def _prep_event(self, origin, event, state=None, auth_events=None):
"""
Args:
origin:
event:
state:
auth_events:
Returns:
Deferred, which resolves to synapse.events.snapshot.EventContext
"""
context = yield self.state_handler.compute_event_context(
event, old_state=state,
)

11
synapse/state.py
View file

@ -177,17 +177,12 @@ class StateHandler(object):
@defer.inlineCallbacks
def compute_event_context(self, event, old_state=None):
""" Fills out the context with the `current state` of the graph. The
`current state` here is defined to be the state of the event graph
just before the event - i.e. it never includes `event`
If `event` has `auth_events` then this will also fill out the
`auth_events` field on `context` from the `current_state`.
"""Build an EventContext structure for the event.
Args:
event (EventBase)
event (synapse.events.EventBase):
Returns:
an EventContext
synapse.events.snapshot.EventContext:
"""
context = EventContext()

15
synapse/storage/background_updates.py
View file

@ -12,6 +12,7 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import synapse.util.async
from ._base import SQLBaseStore
from . import engines
@ -84,24 +85,14 @@ class BackgroundUpdateStore(SQLBaseStore):
self._background_update_performance = {}
self._background_update_queue = []
self._background_update_handlers = {}
self._background_update_timer = None
@defer.inlineCallbacks
def start_doing_background_updates(self):
assert self._background_update_timer is None, \
"background updates already running"
logger.info("Starting background schema updates")
while True:
sleep = defer.Deferred()
self._background_update_timer = self._clock.call_later(
self.BACKGROUND_UPDATE_INTERVAL_MS / 1000., sleep.callback, None
)
try:
yield sleep
finally:
self._background_update_timer = None
yield synapse.util.async.sleep(
self.BACKGROUND_UPDATE_INTERVAL_MS / 1000.)
try:
result = yield self.do_next_background_update(

24
synapse/storage/event_federation.py
View file

@ -201,19 +201,19 @@ class EventFederationStore(SQLBaseStore):
def _update_min_depth_for_room_txn(self, txn, room_id, depth):
min_depth = self._get_min_depth_interaction(txn, room_id)
do_insert = depth < min_depth if min_depth else True
if min_depth and depth >= min_depth:
return
if do_insert:
self._simple_upsert_txn(
txn,
table="room_depth",
keyvalues={
"room_id": room_id,
},
values={
"min_depth": depth,
},
)
self._simple_upsert_txn(
txn,
table="room_depth",
keyvalues={
"room_id": room_id,
},
values={
"min_depth": depth,
},
)
def _handle_mult_prev_events(self, txn, events):
"""

290
synapse/storage/events.py
View file

@ -34,14 +34,16 @@ from canonicaljson import encode_canonical_json
from collections import deque, namedtuple, OrderedDict
from functools import wraps
import synapse
import synapse.metrics
import logging
import math
import ujson as json
# these are only included to make the type annotations work
from synapse.events import EventBase # noqa: F401
from synapse.events.snapshot import EventContext # noqa: F401
logger = logging.getLogger(__name__)
@ -82,6 +84,11 @@ class _EventPeristenceQueue(object):
def add_to_queue(self, room_id, events_and_contexts, backfilled):
"""Add events to the queue, with the given persist_event options.
Args:
room_id (str):
events_and_contexts (list[(EventBase, EventContext)]):
backfilled (bool):
"""
queue = self._event_persist_queues.setdefault(room_id, deque())
if queue:
@ -227,6 +234,17 @@ class EventsStore(SQLBaseStore):
@defer.inlineCallbacks
@log_function
def persist_event(self, event, context, backfilled=False):
"""
Args:
event (EventBase):
context (EventContext):
backfilled (bool):
Returns:
Deferred: resolves to (int, int): the stream ordering of ``event``,
and the stream ordering of the latest persisted event
"""
deferred = self._event_persist_queue.add_to_queue(
event.room_id, [(event, context)],
backfilled=backfilled,
@ -253,6 +271,16 @@ class EventsStore(SQLBaseStore):
@defer.inlineCallbacks
def _persist_events(self, events_and_contexts, backfilled=False,
delete_existing=False):
"""Persist events to db
Args:
events_and_contexts (list[(EventBase, EventContext)]):
backfilled (bool):
delete_existing (bool):
Returns:
Deferred: resolves when the events have been persisted
"""
if not events_and_contexts:
return
@ -554,11 +582,91 @@ class EventsStore(SQLBaseStore):
and the rejections table. Things reading from those table will need to check
whether the event was rejected.
If delete_existing is True then existing events will be purged from the
database before insertion. This is useful when retrying due to IntegrityError.
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]):
events to persist
backfilled (bool): True if the events were backfilled
delete_existing (bool): True to purge existing table rows for the
events from the database. This is useful when retrying due to
IntegrityError.
current_state_for_room (dict[str, (list[str], list[str])]):
The current-state delta for each room. For each room, a tuple
(to_delete, to_insert), being a list of event ids to be removed
from the current state, and a list of event ids to be added to
the current state.
new_forward_extremeties (dict[str, list[str]]):
The new forward extremities for each room. For each room, a
list of the event ids which are the forward extremities.
"""
self._update_current_state_txn(txn, current_state_for_room)
max_stream_order = events_and_contexts[-1][0].internal_metadata.stream_ordering
for room_id, current_state_tuple in current_state_for_room.iteritems():
self._update_forward_extremities_txn(
txn,
new_forward_extremities=new_forward_extremeties,
max_stream_order=max_stream_order,
)
# Ensure that we don't have the same event twice.
events_and_contexts = self._filter_events_and_contexts_for_duplicates(
events_and_contexts,
)
self._update_room_depths_txn(
txn,
events_and_contexts=events_and_contexts,
backfilled=backfilled,
)
# _update_outliers_txn filters out any events which have already been
# persisted, and returns the filtered list.
events_and_contexts = self._update_outliers_txn(
txn,
events_and_contexts=events_and_contexts,
)
# From this point onwards the events are only events that we haven't
# seen before.
if delete_existing:
# For paranoia reasons, we go and delete all the existing entries
# for these events so we can reinsert them.
# This gets around any problems with some tables already having
# entries.
self._delete_existing_rows_txn(
txn,
events_and_contexts=events_and_contexts,
)
self._store_event_txn(
txn,
events_and_contexts=events_and_contexts,
)
# Insert into the state_groups, state_groups_state, and
# event_to_state_groups tables.
self._store_mult_state_groups_txn(txn, events_and_contexts)
# _store_rejected_events_txn filters out any events which were
# rejected, and returns the filtered list.
events_and_contexts = self._store_rejected_events_txn(
txn,
events_and_contexts=events_and_contexts,
)
# From this point onwards the events are only ones that weren't
# rejected.
self._update_metadata_tables_txn(
txn,
events_and_contexts=events_and_contexts,
backfilled=backfilled,
)
def _update_current_state_txn(self, txn, state_delta_by_room):
for room_id, current_state_tuple in state_delta_by_room.iteritems():
to_delete, to_insert = current_state_tuple
txn.executemany(
"DELETE FROM current_state_events WHERE event_id = ?",
@ -608,7 +716,9 @@ class EventsStore(SQLBaseStore):
txn, self.get_current_state_ids, (room_id,)
)
for room_id, new_extrem in new_forward_extremeties.items():
def _update_forward_extremities_txn(self, txn, new_forward_extremities,
max_stream_order):
for room_id, new_extrem in new_forward_extremities.items():
self._simple_delete_txn(
txn,
table="event_forward_extremities",
@ -626,7 +736,7 @@ class EventsStore(SQLBaseStore):
"event_id": ev_id,
"room_id": room_id,
}
for room_id, new_extrem in new_forward_extremeties.items()
for room_id, new_extrem in new_forward_extremities.items()
for ev_id in new_extrem
],
)
@ -643,13 +753,22 @@ class EventsStore(SQLBaseStore):
"event_id": event_id,
"stream_ordering": max_stream_order,
}
for room_id, new_extrem in new_forward_extremeties.items()
for room_id, new_extrem in new_forward_extremities.items()
for event_id in new_extrem
]
)
# Ensure that we don't have the same event twice.
# Pick the earliest non-outlier if there is one, else the earliest one.
@classmethod
def _filter_events_and_contexts_for_duplicates(cls, events_and_contexts):
"""Ensure that we don't have the same event twice.
Pick the earliest non-outlier if there is one, else the earliest one.
Args:
events_and_contexts (list[(EventBase, EventContext)]):
Returns:
list[(EventBase, EventContext)]: filtered list
"""
new_events_and_contexts = OrderedDict()
for event, context in events_and_contexts:
prev_event_context = new_events_and_contexts.get(event.event_id)
@ -662,9 +781,17 @@ class EventsStore(SQLBaseStore):
new_events_and_contexts[event.event_id] = (event, context)
else:
new_events_and_contexts[event.event_id] = (event, context)
return new_events_and_contexts.values()
events_and_contexts = new_events_and_contexts.values()
def _update_room_depths_txn(self, txn, events_and_contexts, backfilled):
"""Update min_depth for each room
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]): events
we are persisting
backfilled (bool): True if the events were backfilled
"""
depth_updates = {}
for event, context in events_and_contexts:
# Remove the any existing cache entries for the event_ids
@ -683,6 +810,21 @@ class EventsStore(SQLBaseStore):
for room_id, depth in depth_updates.items():
self._update_min_depth_for_room_txn(txn, room_id, depth)
def _update_outliers_txn(self, txn, events_and_contexts):
"""Update any outliers with new event info.
This turns outliers into ex-outliers (unless the new event was
rejected).
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]): events
we are persisting
Returns:
list[(EventBase, EventContext)] new list, without events which
are already in the events table.
"""
txn.execute(
"SELECT event_id, outlier FROM events WHERE event_id in (%s)" % (
",".join(["?"] * len(events_and_contexts)),
@ -697,19 +839,16 @@ class EventsStore(SQLBaseStore):
to_remove = set()
for event, context in events_and_contexts:
if context.rejected:
# If the event is rejected then we don't care if the event
# was an outlier or not.
if event.event_id in have_persisted:
# If we have already seen the event then ignore it.
to_remove.add(event)
continue
if event.event_id not in have_persisted:
continue
to_remove.add(event)
if context.rejected:
# If the event is rejected then we don't care if the event
# was an outlier or not.
continue
outlier_persisted = have_persisted[event.event_id]
if not event.internal_metadata.is_outlier() and outlier_persisted:
# We received a copy of an event that we had already stored as
@ -764,37 +903,19 @@ class EventsStore(SQLBaseStore):
# event isn't an outlier any more.
self._update_backward_extremeties(txn, [event])
events_and_contexts = [
return [
ec for ec in events_and_contexts if ec[0] not in to_remove
]
@classmethod
def _delete_existing_rows_txn(cls, txn, events_and_contexts):
if not events_and_contexts:
# Make sure we don't pass an empty list to functions that expect to
# be storing at least one element.
# nothing to do here
return
# From this point onwards the events are only events that we haven't
# seen before.
logger.info("Deleting existing")
def event_dict(event):
return {
k: v
for k, v in event.get_dict().items()
if k not in [
"redacted",
"redacted_because",
]
}
if delete_existing:
# For paranoia reasons, we go and delete all the existing entries
# for these events so we can reinsert them.
# This gets around any problems with some tables already having
# entries.
logger.info("Deleting existing")
for table in (
for table in (
"events",
"event_auth",
"event_json",
@ -816,18 +937,34 @@ class EventsStore(SQLBaseStore):
"redactions",
"room_memberships",
"topics"
):
txn.executemany(
"DELETE FROM %s WHERE event_id = ?" % (table,),
[(ev.event_id,) for ev, _ in events_and_contexts]
)
for table in (
"event_push_actions",
):
txn.executemany(
"DELETE FROM %s WHERE room_id = ? AND event_id = ?" % (table,),
[(ev.event_id,) for ev, _ in events_and_contexts]
)
):
txn.executemany(
"DELETE FROM %s WHERE event_id = ?" % (table,),
[(ev.event_id,) for ev, _ in events_and_contexts]
)
def _store_event_txn(self, txn, events_and_contexts):
"""Insert new events into the event and event_json tables
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]): events
we are persisting
"""
if not events_and_contexts:
# nothing to do here
return
def event_dict(event):
return {
k: v
for k, v in event.get_dict().items()
if k not in [
"redacted",
"redacted_because",
]
}
self._simple_insert_many_txn(
txn,
@ -871,6 +1008,19 @@ class EventsStore(SQLBaseStore):
],
)
def _store_rejected_events_txn(self, txn, events_and_contexts):
"""Add rows to the 'rejections' table for received events which were
rejected
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]): events
we are persisting
Returns:
list[(EventBase, EventContext)] new list, without the rejected
events.
"""
# Remove the rejected events from the list now that we've added them
# to the events table and the events_json table.
to_remove = set()
@ -882,16 +1032,23 @@ class EventsStore(SQLBaseStore):
)
to_remove.add(event)
events_and_contexts = [
return [
ec for ec in events_and_contexts if ec[0] not in to_remove
]
if not events_and_contexts:
# Make sure we don't pass an empty list to functions that expect to
# be storing at least one element.
return
def _update_metadata_tables_txn(self, txn, events_and_contexts, backfilled):
"""Update all the miscellaneous tables for new events
# From this point onwards the events are only ones that weren't rejected.
Args:
txn (twisted.enterprise.adbapi.Connection): db connection
events_and_contexts (list[(EventBase, EventContext)]): events
we are persisting
backfilled (bool): True if the events were backfilled
"""
if not events_and_contexts:
# nothing to do here
return
for event, context in events_and_contexts:
# Insert all the push actions into the event_push_actions table.
@ -921,10 +1078,6 @@ class EventsStore(SQLBaseStore):
],
)
# Insert into the state_groups, state_groups_state, and
# event_to_state_groups tables.
self._store_mult_state_groups_txn(txn, events_and_contexts)
# Update the event_forward_extremities, event_backward_extremities and
# event_edges tables.
self._handle_mult_prev_events(
@ -1011,13 +1164,6 @@ class EventsStore(SQLBaseStore):
# Prefill the event cache
self._add_to_cache(txn, events_and_contexts)
if backfilled:
# Backfilled events come before the current state so we don't need
# to update the current state table
return
return
def _add_to_cache(self, txn, events_and_contexts):
to_prefill = []

10
synapse/storage/state.py
View file

@ -136,6 +136,16 @@ class StateStore(SQLBaseStore):
continue
if context.current_state_ids is None:
# AFAIK, this can never happen
logger.error(
"Non-outlier event %s had current_state_ids==None",
event.event_id)
continue
# if the event was rejected, just give it the same state as its
# predecessor.
if context.rejected:
state_groups[event.event_id] = context.prev_group
continue
state_groups[event.event_id] = context.state_group

54
synapse/util/logcontext.py
View file

@ -12,6 +12,16 @@
# See the License for the specific language governing permissions and
# limitations under the License.
""" Thread-local-alike tracking of log contexts within synapse
This module provides objects and utilities for tracking contexts through
synapse code, so that log lines can include a request identifier, and so that
CPU and database activity can be accounted for against the request that caused
them.
See doc/log_contexts.rst for details on how this works.
"""
from twisted.internet import defer
import threading
@ -309,21 +319,43 @@ def preserve_context_over_deferred(deferred, context=None):
def preserve_fn(f):
"""Ensures that function is called with correct context and that context is
restored after return. Useful for wrapping functions that return a deferred
which you don't yield on.
"""Wraps a function, to ensure that the current context is restored after
return from the function, and that the sentinel context is set once the
deferred returned by the funtion completes.
Useful for wrapping functions that return a deferred which you don't yield
on.
"""
def reset_context(result):
LoggingContext.set_current_context(LoggingContext.sentinel)
return result
# XXX: why is this here rather than inside g? surely we want to preserve
# the context from the time the function was called, not when it was
# wrapped?
current = LoggingContext.current_context()
def g(*args, **kwargs):
with PreserveLoggingContext(current):
res = f(*args, **kwargs)
if isinstance(res, defer.Deferred):
return preserve_context_over_deferred(
res, context=LoggingContext.sentinel
)
else:
return res
res = f(*args, **kwargs)
if isinstance(res, defer.Deferred) and not res.called:
# The function will have reset the context before returning, so
# we need to restore it now.
LoggingContext.set_current_context(current)
# The original context will be restored when the deferred
# completes, but there is nothing waiting for it, so it will
# get leaked into the reactor or some other function which
# wasn't expecting it. We therefore need to reset the context
# here.
#
# (If this feels asymmetric, consider it this way: we are
# effectively forking a new thread of execution. We are
# probably currently within a ``with LoggingContext()`` block,
# which is supposed to have a single entry and exit point. But
# by spawning off another deferred, we are effectively
# adding a new exit point.)
res.addBoth(reset_context)
return res
return g

61
tests/util/test_log_context.py
View file

@ -1,8 +1,10 @@
import twisted.python.failure
from twisted.internet import defer
from twisted.internet import reactor
from .. import unittest
from synapse.util.async import sleep
from synapse.util import logcontext
from synapse.util.logcontext import LoggingContext
@ -33,3 +35,62 @@ class LoggingContextTestCase(unittest.TestCase):
context_one.test_key = "one"
yield sleep(0)
self._check_test_key("one")
def _test_preserve_fn(self, function):
sentinel_context = LoggingContext.current_context()
callback_completed = [False]
@defer.inlineCallbacks
def cb():
context_one.test_key = "one"
yield function()
self._check_test_key("one")
callback_completed[0] = True
with LoggingContext() as context_one:
context_one.test_key = "one"
# fire off function, but don't wait on it.
logcontext.preserve_fn(cb)()
self._check_test_key("one")
# now wait for the function under test to have run, and check that
# the logcontext is left in a sane state.
d2 = defer.Deferred()
def check_logcontext():
if not callback_completed[0]:
reactor.callLater(0.01, check_logcontext)
return
# make sure that the context was reset before it got thrown back
# into the reactor
try:
self.assertIs(LoggingContext.current_context(),
sentinel_context)
d2.callback(None)
except BaseException:
d2.errback(twisted.python.failure.Failure())
reactor.callLater(0.01, check_logcontext)
# test is done once d2 finishes
return d2
def test_preserve_fn_with_blocking_fn(self):
@defer.inlineCallbacks
def blocking_function():
yield sleep(0)
return self._test_preserve_fn(blocking_function)
def test_preserve_fn_with_non_blocking_fn(self):
@defer.inlineCallbacks
def nonblocking_function():
with logcontext.PreserveLoggingContext():
yield defer.succeed(None)
return self._test_preserve_fn(nonblocking_function)