The 'restart' option of the init script cannot restart CH if it was not able to shutdown in `shutdown_wait_unfinished` seconds.
```
# sudo /etc/init.d/clickhouse-server restart
/var/run/clickhouse-server/clickhouse-server.pid file exists and contains pid = 14388.
The process with pid = 14388 is running.
Sent terminate signal to process with pid 14388.
Waiting for server to stop
/var/run/clickhouse-server/clickhouse-server.pid file exists and contains pid = 14388.
The process with pid = 14388 is running.
Waiting for server to stop
...
/var/run/clickhouse-server/clickhouse-server.pid file exists and contains pid = 14388.
Waiting for server to stop
/var/run/clickhouse-server/clickhouse-server.pid file exists and contains pid = 14388.
Waiting for server to stop
...
/var/run/clickhouse-server/clickhouse-server.pid file exists and contains pid = 14388.
Will terminate forcefully.
Code: 425, e.displayText() = DB::ErrnoException: Cannot send kill signal, errno: 3, strerror: No such process (version 21.1.3.32 (official build))
```
The log:
```
2021.02.08 18:57:23.999226 [ 14388 ] {} <Information> Application: Closed connections. But 3 remain. Tip: To increase wait time add to config: <shutdown_wait_unfinished>60</shutdown_wait_unfinished>
2021.02.08 18:57:24.016684 [ 14388 ] {} <Information> Application: Will shutdown forcefully.
2021.02.08 18:58:28.478835 [ 23658 ] {} <Information> Application: Will watch for the process with pid 23659
2021.02.08 18:58:28.478962 [ 23659 ] {} <Information> Application: Forked a child process to watch
2021.02.08 18:58:28.479067 [ 23659 ] {} <Information> StatusFile: Status file /var/run/clickhouse-server/clickhouse-server.pid already exists - unclean restart. Contents: 14388
2021.02.08 18:58:28.479147 [ 23659 ] {} <Information> SentryWriter: Sending crash reports is disabled
2021.02.08 18:58:28.479183 [ 23659 ] {} <Trace> Pipe: Pipe capacity is 1.00 MiB
2021.02.08 18:58:28.532977 [ 23659 ] {} <Information> : Starting ClickHouse 21.1.3.32 with revision 54445, build id: 63BC1671E8C217170F9B6C6346099FD1F76E784F, PID 23659
2021.02.08 18:58:28.533059 [ 23659 ] {} <Information> Application: starting up
```

#endif
#if defined(OS_DARWIN)
    #include <mach-o/dyld.h>
#endif
#include <Common/Exception.h>
#include <Common/ShellCommand.h>
#include <Common/formatReadable.h>
#include <Common/Config/ConfigProcessor.h>
#include <Common/OpenSSLHelpers.h>
#include <Common/hex.h>
#include <common/getResource.h>
#include <common/sleep.h>
#include <IO/ReadBufferFromFileDescriptor.h>
#include <IO/WriteBufferFromFileDescriptor.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/WriteBufferFromFile.h>
#include <IO/MMapReadBufferFromFile.h>
#include <IO/ReadBufferFromMemory.h>
#include <IO/copyData.h>
#include <IO/Operators.h>
#include <readpassphrase.h>
#include <Poco/Util/XMLConfiguration.h>
/** This tool can be used to install ClickHouse without a deb/rpm/tgz package, having only "clickhouse" binary.
  * It also allows to avoid dependency on systemd, upstart, SysV init.
  *
  * The following steps are performed:
  *
  * - copying the binary to binary directory (/usr/bin).
  * - creation of symlinks for tools.
  * - creation of clickhouse user and group.