Commit Graph

17 Commits

Author SHA1 Message Date
Francesco Mazzoli
9e21969637 Slightly tighter error checks 2023-10-11 13:40:46 +01:00
Francesco Mazzoli
440a78510e Add concrete quiet windows to C++ alerts
This together with the previous commits fixes #72.
2023-10-02 23:06:40 +00:00
Francesco Mazzoli
59237ed673 Limit number of open RocksDB files
We got to the point where we had ~4k open SST files per shard, which
meant that we eat up all the available FDs.
2023-09-30 11:08:35 +00:00
Francesco Mazzoli
2679ee7c80 Retry RocksDB transactions if appropriate 2023-09-30 10:44:40 +00:00
Francesco Mazzoli
1d4c4abafd Correctly check that RocksDB txn succeeded
This was caught anyway by the fact that we check that the log index
is what we expect. Would have been very nasty otherwise.

The right thing to do is to check for `Status::TryAgain()` and
retry. `Status::Busy()` should never happen because we never
run transactions concurrently so far.
2023-09-30 09:51:26 +00:00
Francesco Mazzoli
acf4f129f6 Fix CDC txn status tracking
This might be a resolution to #38, although I'm not sure yet.
2023-08-02 13:49:38 +00:00
Francesco Mazzoli
6a52a961eb Split CDC timings to distinguish queue time from exec time 2023-07-27 13:14:12 +00:00
Francesco Mazzoli
889c04766f Do not bump req ids when retrying requests in the CDC
Fixes #29.

The additions to codegen are unrelated -- I was exploring a different
approach based on request equality and I decided to keep those
changes in since they might be useful anyhow.
2023-07-27 11:55:33 +00:00
Francesco Mazzoli
0fc80dfe0f Remove additional CDC status fields
`status()` was racy anyway (the txn might have been gone between
first and second lookup) and these are better solved by the stats
db/graphana anyway.
2023-07-26 19:21:24 +00:00
Francesco Mazzoli
60554ec58d Have bigger histograms, remove other metrics entirely
The `uint16_t` -> `size_t` in `packedSize` is because now
insert stats requests are bigger than `uint16_t`.
2023-07-26 10:01:27 +00:00
Francesco Mazzoli
ff9306f6e3 Add Xmon support to C++ code 2023-07-11 12:13:22 +00:00
Francesco Mazzoli
e2dcd43fea Fix bug in CreateLockedCurrentEdge logic
See comment in `msgs.go`. This would normally have required
entirely new transactions, but since we're not in production yet
I'm going to just change the schema and wipe the current FS.

This also adds in an unrelated change regarding more flexible
blacklisting, which will be required for some additional testing
I'm preparing.
2023-07-04 08:05:42 +00:00
Francesco Mazzoli
6addbdee6a First version of kernel module
Initial version really by Pawel, but many changes in between.

Big outstanding issues:

* span cache reclamation (unbounded memory otherwise...)
* bad block service detection and workarounds
* corrupted blocks detection and workaround

Co-authored-by: Paweł Dziepak <pawel.dziepak@xtxmarkets.com>
2023-05-18 15:29:41 +00:00
Francesco Mazzoli
5bff9b8fae Many, many changes -- tests pass, but FUSE is currently not present
The main thing that's added is full RS support, but a lot of things
were rejigged along the way. The tests are still a bit lacking,
and will be augmented in future commits.
2023-03-03 16:42:22 +00:00
Francesco Mazzoli
e1b8de02dc More assorted improvements 2023-02-15 14:03:53 +00:00
Francesco Mazzoli
85889266b1 Various housekeeping while I get ready to deploy...
...most notably we now produce fully static binaries in an alpine
image.

A few assorted thoughts:

* I really like static binaries, ideally I'd like to run EggsFS
    deployments with just systemd scripts and a few binaries.

* Go already does this, which is great.

* C++ does not, which is less great.

* Linking statically against `glibc` works, but is unsupported.
    Not only stuff like NSS (which `gethostbyname` requires)
    straight up does not work, unless you build `glibc` with
    unsupported and currently apparently broken flags
    (`--enable-static-nss`), but also other stuff is subtly
    broken (I couldn't remember exactly what was broken,
    but see comments such as
    <https://github.com/haskell/haskell-language-server/issues/2431#issuecomment-985880838>).

* So we're left with alternative libcs -- the most popular being
    musl.

* The simplest way to build a C++ application using musl is to just
    build on a system where musl is already the default libc -- such
    as alpine linux.

The backtrace support is in a bit of a bad state. Exception stacktraces
work on musl, but DWARF seems to be broken on the normal release build.

Moreover, libunwind doesn't play well with musl's signal handler:
<https://maskray.me/blog/2022-04-10-unwinding-through-signal-handler>.

Keeping it working seems to be a bit of a chore, and I'm going to revisit
it later.

In the meantime, gdb stack traces do work fine.
2023-01-29 21:41:40 +00:00
Francesco Mazzoli
9adca070ba Convert build system to cmake
Also, produce fully static binaries. This means that `gethostname`
does not work (doesn't work with static glibc unless you build it
with `--enable-static-nss`, which no distro builds glibc with).
2023-01-26 23:20:58 +00:00