Previously, we would compare only the names of the pools when
updating the round robin source selection state.
That meant that if you change the composition of a pool by changing
either the number of the definition of its constituent sources,
that change may not take effect until the corresponding queues
had aged out.
This commit resolves this by comparing both the name and the
composition of the pool when deciding to rebuild the source
selection state.
I noticed while testing the throttle serialization commit
that precedes this one that my directly-in-the-lua-file config
changes weren't being picked up when the config epoch changed.
This commit revises the pooling logic to also check the epoch
in addition to the age of the pooled entries.
This was always present, it just wasn't something we provided a syntax
to specify.
max_burst allows you to control how quickly your throttle budget will
be consumed over the throttle time period.
The default max_burst is equal to the limit you specify, allowing
the full budget to be instantaneously consumed.
refs: https://github.com/KumoCorp/kumomta/issues/326
A customer reported a really long log record like:
```
KumoMTA internal: failed to connect to any candidate hosts: TLS
handshake failed: tls handshake eof, will re-connect in the clear
because opportunistic_tls_reconnect_on_failed_handshake=true, TLS
handshake failed: tls handshake eof ...
```
the site in question had just a single address in its connection plan.
I don't see how we could loop like this unless the cache that is
used to indicate that TLS is broken is being thrashed and the value
that we write to it in response to this event triggering is
never actually sticking in the cache.
This commit introduces a per-session variable to flag that TLS
is broken for this particular site, so that we don't have to rely
on the cached value when we're about to loop and retry.
This controls what we do in an smtp session when we experience a
disconnect during message sending; do we give up on the session,
continue with the connection plan, or try to connect to the same
host again and continue sending any additional messages there?
In the smtp client we internally map IO and timeout errors into
a NotConnected state and break its internal socket, prevent it
from trying to talk to a broken session.
In the dispatcher layer that sits above it, when we consider
whether we need to open a connection, we look only to see if
we have a connection open or not.
If that connection is in a broken state we would keep trying to
use it, because we didn't consider that it might have such
an internal broken state.
This commit fixes up that logic so that we realize that it is
broken, and allow us to move to the next host in the connection
plan.
The purpose of this record is to log additional context about why
a message might end up in the scheduled queue when it hasn't
logged a TransientFailure.
There are a few situations around handling throttles and limits
where we might put a message back into the scheduled queue, without also
logging a TransientFailure record. It's possible that we should
reconsider some of those, but for the moment, there is an observability
hole that needs to be filled.
What this commit does is introduce an `InsertContext` which can hold one
or more `InsertReason`s about why a message is being inserted into the
scheduled queue.
There are 3 primary reasons for insertion:
* Received - the message was just received/injected
* Enumerated - the message was discovered in spool enumeration
* DueTimeWasReached - the message is now due for delivery and is being
popped off the scheduled queue
The additional reasons can be added to the context to provide more
color about what happened.
When a message is added to the scheduled queue, the accumulation
in the InsertContext is examined, and if the context doesn't
indicate that the message was Enumerated and it wasn't also
already logged as a TransientFailure, a `Delay` record is
logged.
The `Delay` record includes in its `response.content` the ordered set of
InsertReasons as well as the delay duration and due time.
Logging Delay records might place undesirable pressure on the
logging storage, so you may wish to disable it via:
```lua
kumo.configure_local_logs {
per_record = {
Delay = {
-- Suppress Delay records
enable = false
}
}
}
```
or similar.
Only the first would take effect because the rule_hash we
computed included all of the actions, so each individual
action would appear to be a duplicate of the first.
This commit ensures that we vary the hash per-action
to avoid this, and augments the integration test
to explicitly verify the result.
The timer object can track latencies in lua code and is helpful for
ad-hoc, explicit "profiling" in your policy script: the latencies are
exported via a prometheus histogram.
I noticed this while reading through the code; we were not updating the
round robin state which we maintain based on the configured egress pool
if the config updates and changes the pool.
We resolve this here by using an arcswap to keep a read-only reference
to the state; since has some async portions it is important to allow it
to continue its management of interior mutability so that it doesn't
acquire a mutex while awaiting on async state.
This is helpful in situations where you need to do things that
are not strictly supported but might just happen to squeak by
if support is claimed for them.
With a specific farsi input string, there are one or more codepoints
that encode with 0x20 as part of their subsequence. The qp_encode
function would confuse those with a space and produce the wrong
output.
This commit fixes that by having the encoder iterate by codepoint
rather than by byte, and then emit the appropriate byte sequences
from there.
We need to ensure that we quote the name portion of a mailbox
if it contains an @-sign in order for the resulting mailbox to
be valid.
quoting here means that the name is enclosed in quotes, but
not that the @-sign is itself quoted with a backslash, so
we have a little hard-coded special case in the string
quoting function for this.
* add send_batch method to kafka mod
* add error messages to returned value and don't log it as error
* add kafka send_batch doc
---------
Co-authored-by: ncai <ncai@chapsvision.com>
A user reported that constructing certain UTF-8 From headers
in the HTTP injection API could produce a From header that
could not be parsed by the DKIM helper when subsequently
attempting to sign the message.
The issue was that the textwrap crate will try to fill out
the wrap, preferring to break an existing word rather than
generating a new line to accommodate one when it would
produce a line that was too long.
This commit adds our own text wrapping algorithm that is
more forgiving.
This adds connection limit/throttle states to the readyq rows
in `kcli queue-summary`, alongside where we would show the
suspension state.
This makes it easier to understand when a given egress path
might be hitting connection limits.
The issue here is:
* If a connection limit was hit (eg: TooManyLeases) then the
readyq maintainer completes its work for that one wakeup
* readyq maintainer then goes to sleep until either 10 minutes
have elapsed, or a new message is moved into the ready queue
* If the system either has no new messages being injected to
that queue, or all of the messages are currently ready,
then those messages will camp out in the ready queue until
10 minutes have elapsed before we try to make another connection.
This hampers the rate of egress.
What this commit does is:
* Introduce a QueueState concept where we can indicate a kind of
"status effect" that applies to a queue. The state has some
human readable context and a time for when the effect was
most recently observed.
* Adds a `connection_limited` state to indicate when we've hit a
connection limit and a `connection_rate_throttled` state when we've
hit the max_connection_rate.
* The ready queue maintainer will reduce its wakeup interval
if it observes that connections have been limited, so that
we can wakeup sooner.
In a separate commit, an API endpoint will be added to expose
these queue states and augment the summary command output.
When used together with an Opportunistic TLS mode, if the handshake
or subsequent EHLO fails, we will re-connect to the current host
and disable TLS.
This is implemented as a recursive solution, which I'm not totally
keen on, but the recursion is limited to a single level so it's
not so bad.
Given a provider with the following config:
```json
"match": [
{
"MXSuffix": "mta5.am0.yahoodns.net"
},
{
"MXSuffix": "mta6.am0.yahoodns.net"
},
{
"MXSuffix": "mta7.am0.yahoodns.net"
}
]
```
(Note that this configuration is not ideal because someone with
`notreallymta5.am0.yahoodns.net` in their MX records will match
this. If you were using SMTP auth for such a site, then you risk
leaking your credentials to it! We should consider adding an exact
match option for this case)
we could never match this because the logic had the inner and outer
loops swapped.
For a provider to match, all of the resolved host names must match
at least one of the MXSuffixes defined in the rule.
The flipped logic prevented that from matching.
Most of this commit is adding stuff to help trace this down
and debug it.
In particular, `resolve-queue-config` will tell you what the
effective value of the get-queue-config event is for a given
queue name, and `resolve-shaping-domain` will show you the shaping
configuration for a (bogus) source.
This option should be used with caution, and ideally only
for trusted networks.
The purpose is to absorb the latency of post-DATA processing
and hide it from the trust injector.
It defers processing that would normally happen in smtp_server_message_received
and instead will, at some (ideally) near-future time trigger an
smtp_server_message_deferred_inject event instead.
This will marginally increase your average injection latency but should
clamp your worst case injection latency much lower because the outliers
will not happen inline with the injecting client.
Wez Furlong
Mike Hillyer
Nathalie Cai