is to know the time to first byte in and time to first byte out. Currently we
have no way to know these all we have is t_starttime. That (t_starttime) tells us
what time the 3 way handshake completed. We don't know when the first
request came in or how quickly we responded. Nor from a client perspective
do we know how long from when we sent out the first byte before the
server responded.
This small change adds the ability to track the TTFB's. This will show up in
BB logging which then can be pulled for later analysis. Note that currently
the tracking is via the ticks variable of all three variables. This provides
a very rough estimate (hz=1000 its 1ms). A follow-on set of work will be
to change all three of these values into something with a much finer resolution
(either microseconds or nanoseconds), though we may want to make the resolution
configurable so that on lower powered machines we could still use the much
cheaper ticks variable.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D24902
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
a single instance: use snd_recover also where sack_newdata was used.
Submitted by: Richard Scheffenegger
Differential Revision: https://reviews.freebsd.org/D18811
a connection can now have a separate tag added to the id.
Obtained from: Lawrence Stewart
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D22866
This makes it possible to retrieve per-connection statistical
information such as the receive window size, RTT, or goodput,
using a newly added TCP_STATS getsockopt(3) option, and extract
them using the stats_voistat_fetch(3) API.
See the net/tcprtt port for an example consumer of this API.
Compared to the existing TCP_INFO system, the main differences
are that this mechanism is easy to extend without breaking ABI,
and provides statistical information instead of raw "snapshots"
of values at a given point in time. stats(3) is more generic
and can be used in both userland and the kernel.
Reviewed by: thj
Tested by: thj
Obtained from: Netflix
Relnotes: yes
Sponsored by: Klara Inc, Netflix
Differential Revision: https://reviews.freebsd.org/D20655
was unlocked and yet the bucket-unlock flag was not
changed to false. This can cause a panic if INVARIANTS
is on and we go through the right path (though rare).
This fixes the correct bug :)
Reported by: syzbot+179a1ad49f3c4c215fa2@syzkaller.appspotmail.com
Reviewed by: tuexen@
Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.
Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)
summits at BSDCan and BSDCam in 2017.
The TCP Blackbox Recorder allows you to capture events on a TCP connection
in a ring buffer. It stores metadata with the event. It optionally stores
the TCP header associated with an event (if the event is associated with a
packet) and also optionally stores information on the sockets.
It supports setting a log ID on a TCP connection and using this to correlate
multiple connections that share a common log ID.
You can log connections in different modes. If you are doing a coordinated
test with a particular connection, you may tell the system to put it in
mode 4 (continuous dump). Or, if you just want to monitor for errors, you
can put it in mode 1 (ring buffer) and dump all the ring buffers associated
with the connection ID when we receive an error signal for that connection
ID. You can set a default mode that will be applied to a particular ratio
of incoming connections. You can also manually set a mode using a socket
option.
This commit includes only basic probes. rrs@ has added quite an abundance
of probes in his TCP development work. He plans to commit those soon.
There are user-space programs which we plan to commit as ports. These read
the data from the log device and output pcapng files, and then let you
analyze the data (and metadata) in the pcapng files.
Reviewed by: gnn (previous version)
Obtained from: Netflix, Inc.
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D11085
