When bootstrapping a new cluster, each replica from replicaset can
be chosen as a leader, but if it is 'read-only', bootstrap will
failed with an error.
Fixed it by eliminating read-only replicas from voting by adding
access rights information to IPROTO_REQUEST_VOTE reply.

Closes #3257

There was an invalid refactoring with forgotten renaming.

The reason of the failures is TLSv1.0/TLSv1.1 brownout on the PyPI side,
see [1] for more information.

[1]: pypa/packaging-problems#130

* Added new coveralls options to sync repo

* Pass travis job to coverage docker

If 'box.cfg.read_only' is false, 'replication' defines at least one
replica (other than itself), but they are not available at the time
of box.cfg execution and replication_connect_quorum is set to zero,
master displays 'orphan' status instead of 'running' since logic
which cnange this state is executed only after successfull connection.

Closes #3278

If a fiber waiting for a read task to complete is cancelled, it will
leave the read iterator immediately, leaving the read task pending.
If the index is dropped before the read task is complete, the task
will attempt to dereference a deleted run upon completion:

    0  0x560b4007dbbc in print_backtrace+9
    1  0x560b3ff80a1d in _ZL12sig_fatal_cbiP9siginfo_tPv+1e7
    2  0x7f52b09190c0 in __restore_rt+0
    3  0x7f52af6ea30a in bzero+5a
    4  0x560b3ffc7a99 in mempool_free+2a
    5  0x560b3ffcaeb7 in vy_page_read_cb_free+47
    6  0x560b400806a2 in cbus_call_done+3f
    7  0x560b400805ea in cmsg_deliver+30
    8  0x560b40080e4b in cbus_process+51
    9  0x560b4003046b in _ZL10tx_prio_cbP7ev_loopP10ev_watcheri+2b
    10 0x560b4023d86e in ev_invoke_pending+ca
    11 0x560b4023e772 in ev_run+5a0
    12 0x560b3ff822dc in main+5ed
    13 0x7f52af6862b1 in __libc_start_main+f1
    14 0x560b3ff801da in _start+2a
    15 (nil) in +2a

Fix this by elevating the run reference counter per each read task.

Note, currently we use vy_run::refs not only as a reference counter, but
also as a counter of slices created for the run - see how we compare it
to vy_run::compacted_slice_count in vy_task_compact_complete(). This
isn't going to work anymore, obviously. Now we need to count slices
created per each run in a separate counter, vy_run::slice_count. Anyway,
it was a rather dubious hack to abuse reference counter for counting
slices and it's good to finally get rid of it.

We use ERRINJ_DOUBLE for all other timeout injections. This makes them
more flexible as we can inject an arbitrary timeout in tests, not just
enable some hard-coded timeout. Besides, it makes tests easier to
follow. So let's use ERRINJ_DOUBLE for ERRINJ_VY_READ_PAGE_TIMEOUT too.

If a space has no indexes, index_find() will return NULL, which will be
happily dereferenced by on_replace_dd_sequence(). Looks like this bug
goes back to the time when we made index_find() exception-free and
introduced index_find_xc() wrapper. Fix it and add a test case.

* Remove rewriting format of default logger in case of syslog option.
* Add facility option parsing and use parsed results in format message
  according to RFC3164. Possible values and default value of syslog
  facility are taken from nginx (https://nginx.ru/en/docs/syslog.html)
* Move initialization of logger type and format fucntion before
  initialization of descriptor in log_XXX_init, so that we can test
  format function of syslog logger.

Closes gh-3244.

Filed gh-3311 to remove this export soon.

Fixes #3310.

If the size of a transaction is greater than the configured memory
limit (box.cfg.vinyl_memory), the transaction will hang on commit
for 60 seconds (box.cfg.vinyl_timeout) and then fail with the
following error message:

  Timed out waiting for Vinyl memory quota

This is confusing. Let's fail such transactions immediately with
OutOfMemory error.

Closes #3291

In case of sudden power-loss, if data was not written to WAL but
already sent to remote replica, local can't recover properly and
we have different datasets. Fix it by using remote replica's data
and LSN comparison.

Based on @GeorgyKirichenko proposal and @locker race free check.

Closes #3210

Stay in orphan (read-only) mode until local vclock is lower than
master's to make sure that datasets are the same across replicaset.
Update replication/catch test to reflect the change.

Suggested by @kostja

Needed for #3210

Closes #3148

EV_USE_REALTIME and EV_USE_MONOTONIC, which force libev to use
clock_gettime, are enabled automatically on Linux, but not on OS X. We
used to forcefully enable them for performance reasons, but this broke
compilation on certain OS X versions and so was disabled by commit
d36ba279 ("Fix gh-1777: clock_gettime detected but unavailable in
macos"). Today we need these features enabled not just because of
performance, but also to avoid crashes when time changes on the host -
see issue #2527 and commit a6c87bf9 ("Use ev_monotonic_now/time
instead of ev_now/time for timeouts"). Fortunately, we have this cmake
defined macro HAVE_CLOCKGETTIME_DECL, which is set if clock_gettime is
available. Let's enable EV_USE_REALTIME and EV_USE_MONOTONIC if this
macro is defined.

Closes #3299

The bug was that logging we passed to function write
number of bytes which may be more than size of buffer.
This may happen because formatting log string we use vsnprintf which
returns number of bytes would be written to buffer, not the actual
number.

Fix this with limiting number of bytes passing to write function.

Close #3248

* Refactor tests.
* Add ev_async and fiber_cond for thread-safe log_rotate usage.

Follow up #3015

Fix race condition in test on log_rotate.
Test opened file that must be created by log_rotate and read from it.
But as log_rotate is executed in separate thread, file may be not
created or log may be not written yet by the time of opening in test.

Fix this with waiting creation and reading the line.

Netbox does not need nullability or collation info, but some
customers do. Lets fill index parts with these fields.

Fixes #3256

* session_run_on_disconnect_triggers is called only if there are
corresponding triggers so move session_storage_cleanup to
session_destroy.
* fix session storage cleanup path: use
"box.session.aggregate_storage[sid]" instead of
"session.aggregate_storage[sid]" (what was wrong)

Fixed #3279

Empty strings should be ignored, rather than throw an error.

Passing only empty strings (or nothing) to `pathjoin` will return '.' which means the current directory

Every path part passed to `pathjoin` is now converted to a string

The `gsub('/+', '/')` call already does what the removed code does, so avoid the unnecessary work
Simply check if the result equals '/' before removing a trailing '/'.

The previous check did extra work for no gain.

It is possible to discard non-sent responses using a special
sequence of requests and yields. In details: if DML requests
yield on commit too long, there are fast read requests, and a
network is saturated, then some non-sent DML responses are
discarded.

Closes #3255

A vinyl space can be altered in such a way, that key definitions
of indexes are not changed, but comparators do. It is because
space format reset can make some indexed fields optional.

To be able update key definitions in place, they must not be used
in a worker thread. So lets copy key_defs for a worker, and
update index key definitions in place.

An alternative is key_defs reference counting, but there is open
questions what to do in key_defs in mems, ranges, iterators,
runs, slices. Now lets do a hotfix of a crash, and then
refactoring.

Closes #3229

Use key_def_delete instead. It is more safe to use one
destructor everywhere for a case, if in a future key_def will not
be deleted by simple free().

Under FreeBSD getline prototype is not provided by
default due to compatibility problems.
Get rid of getline (use fgets instead).
Based on @locker proposal.

Closes #3217.

log_rotate writes informational message only in plain format,
which is inappropriate when logger is configured to log in json format.

Fix it with replacing write with say_info which is safe
because it is ev signal callback not signal handler.

Fix bug say_format in json formatting,
Log message was invalid in several cases.

Closes #2987

Current log rotation is not async signal safe.
In order to make it so refactor signal handling
with ev_signal.

Log rotation for each logger performs in separate
coio_task to provide async and thread-safe execution.

Relates #3015

Remove yielding and waiting task complete in coio_task_post
in case if timeout is zero.
This patch is inspired by the need in log_rotate posting coio
task. This post should not yield there because the implementation
of multiple loggers works with linked list structure of loggers
which is not fiber-safe.

When a space format is updated, a new min field count must be
calculated before a new format construction to check that some
of fields became optional.

Part of #3229

When scanning a secondary index, we actually track each tuple in the
transaction manager twice - as a part of the interval read from the
secondary index and as a point in the primary index when retrieving
the full tuple. This bloats the read set - instead of storing just one
interval for a range request, we also store each tuple returned by it,
which may count to thousands. There's no point in this extra tracking,
because whenever we change a tuple in the primary index, we also update
it in all secondary indexes. So let's remove it to save us some memory
and cpu cycles.

This is an alternative fix for #2534
It should also mitigate #3197

We never use vy_point_lookup directly, instead we open vy_read_iterator,
which automatically falls back on vy_point_lookup if looking for exact
match (EQ + full key). Due to this we can't add a new point lookup
specific argument (we would have to propagate it through the read
iterator, which is ugly). Let's call vy_point_lookup directly when we
know that vy_read_iterator will fall back on it anyway.

This reverts commit a31c2c10.

The commit reverted by this patch forces all autocommit SELECTs to open
a read view immediately, as a result they can't update tuple cache.
Turned out that one of our customers intensively uses such SELECTs, and
disabling cache for them results in performance degradation.

The reason why that commit was introduced in the first place was to
avoid read set bloating for big SELECTs (e.g. space.count()): currently
we track not only read interval boundaries, but also each tuple fetched
from the primary index if it is a secondary index that is being scanned.
However, it doesn't seem that we really need to do that - tracking an
interval read from a secondary index guarantees that if a tuple returned
by the iterator is modified the transaction will be aborted and so
there's no need to track individual tuples read from the primary index.

That said, let's revert this commit and instead remove point lookup
tracking in case it is a secondary index that is being scanned (done
later in the series).