ev_timer.at was used as timeout. But after ev_timer_start() it
turns into the deadline - totally different value.

The patch makes sure ev_timer.at is not used in raft at all.

To test that the fakeev subsystem is patched to start its time not
from 0. Otherwise ev_timer.at often really matched the timeout
even for an active timer.

It used to crash if done during election on a node voted for
anybody, it is a candidate, it doesn't know a leader yet, but has
a WAL write in progress.

Thus it could only happen if the term was bumped by a message from
a non-leader node and wasn't flushed to the disk yet.

The patch makes the reconfig check if there is a WAL write in
progress. Then don't do anything.

Could also check for volatile vote instead of persistent, but it
would create the same problem for the case when started writing
vote for self and didn't finish yet. Reconfig would crash.

Add GitHub Actions workflows for Fedora 35
Closes: #6692

The test has a function wait_repl() which tries to wait until the data
is replicated to the other node for a tiny timeout (0.2 seconds)

This didn't cause issues in the past, but it became an issue after
applier in thread introduction.

Let's use the default test_run:wait_cond() approach instead of a custom
one. This way we increase waiting timeout (making the test pass with a
higher chance).

Follow-up #6329

Follow-up #6329

It's reported that in master-slave setup replicas often have higher CPU
usage than their replication masters. Moreover, it's easy for a replica
to start falling behind the master.

The reason for that is the additional work load on replica's tx thread  as
compared to master. While master typically splits request processing into 2
threads: iproto, which decodes the requests, and tx, which applies them,
replica performs both tasks in the tx thread.

This is due to replication architecture: replica handles master
connection by a single fiber in the tx thread. The fiber first decodes the
incoming requests and then applies them.

Teach replicas to decode the incoming replication stream in a separate
thread. This way tx thread doesn't waste processing time on row
decoding.

Each applier thread may serve several appliers, and the total number of
applier threads is controlled by a new configuration option -
`replication_threads`, with default value `1` (meaning, a single
thread is spawned to handle all the appliers.

Closes #6329

@TarantoolBot document
Title: New configuration option - `replication_threads`

It's now possible to specify how many threads will be spawned to decode
the incoming replication stream.

The default value is '1', meaning a single thread will handle all
incoming replication streams.

You may set the value to anything from 1 to 1000. When there are
multiple replication threads, connections to serve are evenly
distributed between the threads.

This commit adds SSL context to iostream_ctx and a new kind of error for
SSL connections.

The SSL context is created if the target URI has transport=ssl
parameter. If transport=plain or absent, it will be set to NULL and
plain streams will be created as before. For other values of the
transport parameter, an error is raised. Note, this is just a stub -
an attempt to create an SSL context always currently fails with
"SSL not available" error. It is supposed to be implemented in
EE build.

The new kind of error is currently only used for decoding errors from
MsgPack and never raised. It will be raised by the actual implementation
of SSL stream.

Use table.equals for comparing table-valued configuration parameters
instead of ipairs. Needed to trigger reconfiguraiton if the new URI
differs from the old one only by parameters, e.g.:

  box.cfg{listen = {uri = 3301, params = {transport = 'plain'}}}
  box.cfg{listen = {uri = 3301, params = {transport = 'ssl'}}}

No test is added, because currently there's no URI parameters handled
by box. The next commit adds the 'transport' parameter and a test that
wouldn't pass without this commit.

IO stream context (iostream_ctx) stores information needed to construct
an iostream object.  A context is created from URI and mode, which is
either server or client. Currently, both parameters are ignored and a
newly created context always constructs plain streams. However, in
future we will create SSL streams for certain URIs. That's when we'll
need the mode (SSL connection is asymmetrical).

In SSL implementation iostream::ctx would point to a SSL object, while
a SSL_CTX object would be used for creating streams. Let's rename ctx to
data to avoid confusion.

The function is used only once, in box_sync_replication. Inlining it
makes the code more robust - it allows us to throw from applier_new.

Currently, we always create a plain stream, but soon there will be an
option to create an encrypted stream so let's pass iostream, which will
encapsulate this information, instead of fd to the accept callback. The
iostream will be created by evio in accordance with the settings passed
in uri parameters so uri won't be needed in the accept callback.

It's been many years since it was last used. I'm tired of patching it
whenever I need to update evio_service. Besides, it decreases code
coverage. So let's finally drop it. After all, it's just a few lines
of trivial code that can be rewritten from scratch any time we need.

The function creates a plain iostream so let's rename it accordingly.

There are two acceptable ways of calling `connect` - as a method of
the net.box module or as a function defined in the module:

```lua
local net = require('net.box')
net.connect(...)
net:connect(...)
```

We determine which one is used by checking the type of the first
argument: if it's a table, we assume that the function is called as
a method. However, the first argument can be a table itself - in case
it's a URI given in the extended format.

Let's fix this check by comparing the first argument against the net.box
module. Let's also add a test checking all possible combinations of
`connect` arguments.

Follow-up 0badb413 ("net.box: pass uri
instead of host and port to state machine").

The commit fixes the following test failure:

```
[011] engine/errinj_ddl.test.lua                      memtx           [ fail ]
[011]
[011] Test failed! Result content mismatch:
[011] --- engine/errinj_ddl.result      Tue Jan 18 15:28:21 2022
[011] +++ var/rejects/engine/errinj_ddl.reject  Tue Jan 18 15:28:26 2022
[011] @@ -343,7 +343,7 @@
[011]  s:create_index('sk', {parts = {2, 'unsigned'}}) -- must fail
[011]  ---
[011]  - error: Duplicate key exists in unique index "sk" in space "test" with old tuple
[011] -    - [101, 101, "xxxxxxxxxxxxxxxx"] and new tuple - [100, 101]
[011] +    - [100, 101] and new tuple - [101, 101, "xxxxxxxxxxxxxxxx"]
[011]  ...
[011]  ch:get()
[011]  ---
```

The test is inherently racy: a conflicting tuple may be inserted to the
new index either by the index build procedure or by the test fiber doing
DML in the background. The error messages will disagree regarding what
tuple should be considered old and which one new. Let's match the error
message explicitly.

The failure was introduced by d11fb306
("box: change ER_TUPLE_FOUND message") which enhanced error messages
with conflicting tuples.

Testing tuple field count overflow handling requires creating a severely
large tuple with box.schema.FIELD_MAX (INT32_MAX) fields: introduce an
error injection for testing this corner case.

Fixes #6684

* Enable parallel invocation of fragile tests

The commit fixes the following test failure:

```
[082] vinyl/gh-4810-dump-during-index-build.test.lua                  Test timeout of 310 secs reached	[ fail ]
[082]
[082] Test failed! Result content mismatch:
[082] --- vinyl/gh-4810-dump-during-index-build.result	Thu Dec  9 05:31:17 2021
[082] +++ /build/usr/src/debug/tarantool-2.10.0~beta1.324.dev/test/var/rejects/vinyl/gh-4810-dump-during-index-build.reject	Thu Dec  9 06:51:03 2021
[082] @@ -117,34 +117,3 @@
[082]  for i = 1, ch:size() do
[082]      ch:get()
[082]  end;
[082] - | ---
[082] - | ...
[082] -
...
```

The test hangs waiting for the test fibers to exit. There are two test
fibers - one builds an index, another populates the test space. The
latter uses pcall so it always returns. The one that builds an index,
however, doesn't. The problem is index build may fail because it builds
a unique index while the fiber populating the space may insert
non-unique values. Fix this by building a non-unique index instead,
which should never fail. To reproduce the issue the test checks is fixed
one can build any index, unique or non-unique, so it should be fine.

Closes #5508

The commit fixes the following test failure:

```
[005] vinyl/gh.test.lua                                               [ fail ]
[005]
[005] Test failed! Result content mismatch:
[005] --- vinyl/gh.result	Mon Dec 13 15:03:45 2021
[005] +++ /root/actions-runner/_work/tarantool/tarantool/test/var/rejects/vinyl/gh.reject	Fri Dec 17 10:41:24 2021
[005] @@ -716,7 +716,7 @@
[005]  ...
[005]  test_run:wait_cond(function() return finished == 2 end)
[005]  ---
[005] -- true
[005] +- false
[005]  ...
[005]  s:drop()
[005]  ---
```

The reason of the failure is that the fiber doing checkpoints fails,
because a checkpoint may be already running by the checkpoint daemon.
Invoke box.snapshot() under pcall to make the test more robust.

Part of #5141

The commit fixes the following test failure:

```
[019] vinyl/deferred_delete.test.lua                                  [ fail ]
[019]
[019] Test failed! Result content mismatch:
[019] --- vinyl/deferred_delete.result	Tue Jan 11 11:10:22 2022
[019] +++ /build/usr/src/debug/tarantool-2.10.0~beta2.37.dev/test/var/rejects/vinyl/deferred_delete.reject	Fri Jan 14 11:45:26 2022
[019] @@ -964,7 +964,7 @@
[019]  ...
[019]  sk:stat().disk.dump.count -- 1
[019]  ---
[019] -- 1
[019] +- 0
[019]  ...
[019]  sk:stat().rows - dummy_rows -- 120 old REPLACEs + 120 new REPLACEs + 120 deferred DELETEs
[019]  ---
```

The test checks that compaction of a primary index triggers dump of
secondary indexes of the same space, because it generates deferred
DELETE statements. There's no guarantee that by the time compaction
completes, secondary index dump have been completed as well, because
compaction may ignore the memory quota (it uses vy_quota_force_use in
vy_deferred_delete_on_replace). Make the check more robust by using
wait_cond.

Follow-up #5089

It's better than hand-written busy-wait.

The commit fixes the following test failure:

```
[013] vinyl/gc.test.lua                                               [ fail ]
[013]
[013] Test failed! Result content mismatch:
[013] --- vinyl/gc.result	Fri Dec 24 12:27:33 2021
[013] +++ /build/usr/src/debug/tarantool-2.10.0~beta2.18.dev/test/var/rejects/vinyl/gc.reject	Thu Dec 30 10:29:29 2021
[013] @@ -102,7 +102,7 @@
[013]  ...
[013]  check_files_number(2)
[013]  ---
[013] -- true
[013] +- null
[013]  ...
[013]  -- All records should have been purged from the log by now
[013]  -- so we should only keep the previous log file.
```

The reason of the failure is that vylog files are deleted asynchronously
(`box.snapshot()` doesn't wait for `unlink` to complete) since commit
8e429f4b ("wal: remove old xlog files
asynchronously"). So to fix the test, we just need to make the test wait
for garbage collection to complete.

Follow-up #5383

When `slab_get` is called from `region_alloc` or `ibuf_alloc` first
of all we try to calculate order of appropriate slab. But there is
no check that requested size with slab meta is <= UINT32_MAX, that
leads to assertion failer in `slab_order` function. There is no
need for this assertion we should return `cache->order_max + 1`
for this case.

Closes #6726

This required some test refactoring for tests which rely on quorum being
"1" by default.

Closes #5966
Prerequisite #6471

This patch brings consistency to OSX workflow names with other workflow
names.

The following changes were made:

  * Arch suffix changed (arm64 -> aarch64)
  * Minor OS version removed (11_2 -> 11)
  * Specific options moved to the end of the workflow name
    (osx_debug_xyz.yml -> osx_xyz_debug.yml)

Closes tarantool/tarantool-qa#149

Now `## bugfix/luajit` and `## bugfix/LuaJIT` entries will form one
section.

Now one can write either `## bugfix/luajit` or `## bugfix/LuaJIT`. The
latter will NOT be transformed into `### Luajit` anymore. Both variants
now give `### LuaJIT` section inside `## Bugs fixed` section.

See `REDEFINITIONS` variable inside the script to understand how well
known headers (such as `## <...>/LuaJIT`) are prettified.

There is a problem with section grouping, when headers are written in
lower/title/mixed case. It'll be resolved in a next commit.

We run the script in CI as linter (see PR #6701), so it should handle
lack of any changelog entries gracefully.

Previously the script mistakely requires at least one feature and at
least one bugfix. However it is quite natural to have only bugfixes in a
bugfix release. Moreover, we added the script into CI as linter (see
PR #6701), so it should work even when we just start filling release
notes.

Git does not store empty directories, but it is convenient for us to
have this directory always.

Patch allows to run fuzzing in PR where label 'full-ci' is set.
Complememts a patch in commit "ci: enable fuzzing for *-full-ci
branches" (0115aab0).

Follows up #6630

Fuzzing workflow has been disabled due to warnings (treated by errors)
on compilation with Clang 14 that is used as a default compiler in
OSS-Fuzz infrastructure and missed libunwind in a test env where fuzzers
run. Compilation warnings were fixed in a previous commit and problem
with missed libunwind library has been resolved by patch to OSS-Fuzz
[1].

Follows up #6681

1. https://github.com/google/oss-fuzz/pull/7110

Part of #6681

Add ubuntu-impish workflow, which runs on push and pull-requests.

Closes #6566

The test for the 'unicode_de__phonebook_s3' collation from
sql-tap/collation_unicode.test.lua fail if the ICU version >= 70.1.
So let's temporarily mark it as unstable until the issue is resolved.

See for more details tarantool/tarantool#6695.

Fuzzing is disabled until #6681 is resolved.

Now it is not possible to run fuzzing on CI without merge to master
branch. Last time we missed [1] a broken compilation on merging new
fuzzers to master [2]. This patch enables fuzzing for branches with
postfix 'full-ci'.

1. https://github.com/tarantool/tarantool/pull/6757
2. https://github.com/tarantool/tarantool/pull/6627