Files
MaxScale/server/modules/routing/readwritesplit/rwsplit_session_cmd.cc
Markus Mäkelä 34008082e5 Rename to has_session_commands
This way it is similar to other member functions.
2018-04-10 15:30:28 +03:00

146 lines
4.8 KiB
C++

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2020-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#include "readwritesplit.hh"
#include "rwsplitsession.hh"
#include <stdio.h>
#include <strings.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <maxscale/router.h>
using namespace maxscale;
/**
* Functions for session command handling
*/
static std::string extract_error(GWBUF* buffer)
{
std::string rval;
if (MYSQL_IS_ERROR_PACKET(((uint8_t *)GWBUF_DATA(buffer))))
{
size_t replylen = MYSQL_GET_PAYLOAD_LEN(GWBUF_DATA(buffer));
char replybuf[replylen];
gwbuf_copy_data(buffer, 0, gwbuf_length(buffer), (uint8_t*)replybuf);
std::string err;
std::string msg;
err.append(replybuf + 8, 5);
msg.append(replybuf + 13, replylen - 4 - 5);
rval = err + ": " + msg;
}
return rval;
}
/**
* Discards the slave connection if its response differs from the master's response
*
* @param backend The slave Backend
* @param master_cmd Master's reply
* @param slave_cmd Slave's reply
*/
static void discard_if_response_differs(SRWBackend backend, uint8_t master_cmd, uint8_t slave_cmd)
{
if (master_cmd != slave_cmd)
{
MXS_WARNING("Slave server '%s': response (0x%02hhx) differs "
"from master's response(0x%02hhx). Closing slave "
"connection due to inconsistent session state.",
backend->name(), slave_cmd, master_cmd);
backend->close(mxs::Backend::CLOSE_FATAL);
}
}
void RWSplitSession::process_sescmd_response(SRWBackend& backend, GWBUF** ppPacket)
{
if (backend->has_session_commands())
{
/** We are executing a session command */
if (GWBUF_IS_TYPE_SESCMD_RESPONSE((*ppPacket)))
{
uint8_t cmd;
gwbuf_copy_data(*ppPacket, MYSQL_HEADER_LEN, 1, &cmd);
uint8_t command = backend->next_session_command()->get_command();
uint64_t id = backend->complete_session_command();
MXS_PS_RESPONSE resp = {};
bool discard = true;
if (command == MXS_COM_STMT_PREPARE && cmd != MYSQL_REPLY_ERR)
{
// This should never fail or the backend protocol is broken
ss_debug(bool b = )mxs_mysql_extract_ps_response(*ppPacket, &resp);
ss_dassert(b);
backend->add_ps_handle(id, resp.id);
}
if (m_recv_sescmd < m_sent_sescmd && id == m_recv_sescmd + 1)
{
if (!m_current_master || !m_current_master->in_use() || // Session doesn't have a master
m_current_master == backend) // This is the master's response
{
/** First reply to this session command, route it to the client */
++m_recv_sescmd;
discard = false;
/** Store the master's response so that the slave responses can
* be compared to it */
m_sescmd_responses[id] = cmd;
if (cmd == MYSQL_REPLY_ERR)
{
MXS_INFO("Session command no. %lu failed: %s",
id, extract_error(*ppPacket).c_str());
}
else if (command == MXS_COM_STMT_PREPARE)
{
/** Map the returned response to the internal ID */
MXS_INFO("PS ID %u maps to internal ID %lu", resp.id, id);
m_qc.ps_id_internal_put(resp.id, id);
}
// Discard any slave connections that did not return the same result
for (SlaveResponseList::iterator it = m_slave_responses.begin();
it != m_slave_responses.end(); it++)
{
discard_if_response_differs(it->first, cmd, it->second);
}
m_slave_responses.clear();
}
else
{
/** Record slave command so that the response can be validated
* against the master's response when it arrives. */
m_slave_responses.push_back(std::make_pair(backend, cmd));
}
}
else
{
discard_if_response_differs(backend, m_sescmd_responses[id], cmd);
}
if (discard)
{
gwbuf_free(*ppPacket);
*ppPacket = NULL;
}
}
}
}