hcq/MaxScale
hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MXS-1926: Ignore server shutdown errors

Browse Source 
If the server sends a server shutdown error, it is safe for readwritesplit
to ignore it. When the TCP connection is closed, the router error handling
will discard the connection, optionally replacing it.
This commit is contained in:
Markus Mäkelä 2018-06-20 00:34:16 +03:00
parent b018781764
commit 980caa5be5
No known key found for this signature in database
GPG Key ID: 72D48FCE664F7B19
1 changed files with 33 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
server/modules/routing/readwritesplit/readwritesplit.cc
View File

@ -1123,6 +1123,22 @@ static json_t* diagnostics_json(const MXS_ROUTER *instance)
return rval;
}
static bool connection_was_killed(GWBUF* buffer)
{
bool rval = false;
if (mxs_mysql_is_err_packet(buffer))
{
uint8_t buf[2];
// First two bytes after the 0xff byte are the error code
gwbuf_copy_data(buffer, MYSQL_HEADER_LEN + 1, 2, buf);
uint16_t errcode = gw_mysql_get_byte2(buf);
rval = errcode == ER_CONNECTION_KILLED;
}
return rval;
}
static void log_unexpected_response(SRWBackend& backend, GWBUF* buffer)
{
if (mxs_mysql_is_err_packet(buffer))
@ -1135,18 +1151,9 @@ static void log_unexpected_response(SRWBackend& backend, GWBUF* buffer)
uint16_t errcode = MYSQL_GET_ERRCODE(data);
std::string errstr((char*)data + 7, (char*)data + 7 + len - 3);
if (errcode == ER_CONNECTION_KILLED)
{
MXS_INFO("Connection from '%s'@'%s' to '%s' was killed",
backend->dcb()->session->client_dcb->user,
backend->dcb()->session->client_dcb->remote,
backend->name());
}
else
{
MXS_WARNING("Server '%s' sent an unexpected error: %hu, %s",
backend->name(), errcode, errstr.c_str());
}
ss_dassert(errcode != ER_CONNECTION_KILLED);
MXS_WARNING("Server '%s' sent an unexpected error: %hu, %s",
backend->name(), errcode, errstr.c_str());
}
else
{
@ -1192,11 +1199,20 @@ static void clientReply(MXS_ROUTER *instance,
if (backend->get_reply_state() == REPLY_STATE_DONE)
{
/** If we receive an unexpected response from the server, the internal
* logic cannot handle this situation. Routing the reply straight to
* the client should be the safest thing to do at this point. */
log_unexpected_response(backend, writebuf);
MXS_SESSION_ROUTE_REPLY(backend_dcb->session, writebuf);
if (connection_was_killed(writebuf))
{
// The connection was killed, we can safely ignore it. When the TCP connection is
// closed, the router's error handling will sort it out.
gwbuf_free(writebuf);
}
else
{
/** If we receive an unexpected response from the server, the internal
* logic cannot handle this situation. Routing the reply straight to
* the client should be the safest thing to do at this point. */
log_unexpected_response(backend, writebuf);
MXS_SESSION_ROUTE_REPLY(backend_dcb->session, writebuf);
}
return;
}