// cases to test:
// child server, stopped normally; reattach, start
// non-direct child server, killed abnormally; reattach, start (->error), remove pid.txt; start
// non-direct child server, still running; reattach, start (->error), stop, start
// child server, still running; reattach, start (-> error)
// child server, still running; reattach, stop, start.
// non-direct child server, still running; reattach, stop, start.
func (s *S) TestAttachServer(c *C) {
// Create a cookie so that we know we are reattaching to the same instance.
conn, _ := s.init(c)
_, err := conn.Create("/testAttachCookie", "testAttachCookie", 0, zk.WorldACL(zk.PERM_ALL))
c.Assert(err, IsNil)
s.checkCookie(c)
s.zkServer.Stop()
s.zkServer = nil
s.testAttachServer(c, (*S).startServer)
s.testAttachServer(c, (*S).startServerIndirect)
s.testAttachServerAbnormalTerminate(c, (*S).startServer)
s.testAttachServerAbnormalTerminate(c, (*S).startServerIndirect)
srv, err := zk.AttachServer(s.zkTestRoot)
c.Assert(err, IsNil)
s.zkServer = srv
err = s.zkServer.Start()
c.Assert(err, IsNil)
conn, _ = s.init(c)
err = conn.Delete("/testAttachCookie", -1)
c.Assert(err, IsNil)
}
func (s *S) testAttachServerAbnormalTerminate(c *C, start func(*S, *C, bool)) {
start(s, c, true)
// try attaching to it and starting - it should fail, because pid.txt
// won't have been removed.
srv, err := zk.AttachServer(s.zkTestRoot)
c.Assert(err, IsNil)
err = srv.Start()
c.Assert(err, NotNil)
// stopping it should bring things back to normal.
err = srv.Stop()
c.Assert(err, IsNil)
err = srv.Start()
c.Assert(err, IsNil)
s.checkCookie(c)
err = srv.Stop()
c.Assert(err, IsNil)
}
// startServer starts a ZooKeeper server, and terminates it abnormally
// if abort is true.
func startServer(runDir string, abort bool) error {
srv, err := zk.AttachServer(runDir)
if err != nil {
return fmt.Errorf("cannot attach to server at %q: %v", runDir, err)
}
if err := srv.Start(); err != nil {
return fmt.Errorf("cannot start server: %v", err)
}
if abort {
// Give it time to start up, then kill the server process abnormally,
// leaving the pid.txt file behind.
time.Sleep(0.5e9)
p, err := srv.Process()
if err != nil {
return fmt.Errorf("cannot get server process: %v", err)
}
defer p.Release()
if err := p.Kill(); err != nil {
return fmt.Errorf("cannot kill server process: %v", err)
}
}
return nil
}
func (s *S) testAttachServer(c *C, start func(*S, *C, bool)) {
start(s, c, false)
s.checkCookie(c)
// try attaching to it while it is still running - it should fail.
srv, err := zk.AttachServer(s.zkTestRoot)
c.Assert(err, IsNil)
err = srv.Start()
c.Assert(err, NotNil)
// stop it and then start it again - it should succeed.
err = srv.Stop()
c.Assert(err, IsNil)
err = srv.Start()
c.Assert(err, IsNil)
s.checkCookie(c)
err = srv.Stop()
c.Assert(err, IsNil)
}