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

MXS-2555 Simple Smart Router

Browse Source 
Does the measurments, usage of the same  and persistence to file.
Kill is not implemented, so waits for all clusters to fully responds

The performance data uses a mutex and the persistence data file
is written while holding the mutex. This obviously needs to be
improved, but this commit shows the working concept.
This commit is contained in:
Niclas Antti
2019-06-11 11:07:53 +03:00
parent c47a2d32fa
commit 1241300494
5 changed files with 381 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

86
server/modules/routing/smartrouter/smartsession.cc
View File

@ -12,34 +12,16 @@
*/
#include "smartsession.hh"
#include "smartrouter.hh"
#include "performance.hh"
#include <maxscale/modutil.hh>
#include <maxsql/mysql_plus.hh>
// TO_REVIEW:
// This is the base for Smart Router. It will currently route any normal query to all
// configured routers and only use the first response to forward back to the client.
// However, it should be reviewed as if it could actually be put in front of
// several current routers (several readwritesplits and readconnroutes) and
// succeed for anything but local infile.
// TO_REVIEW. There is no need to go through the functionality with a very, very fine-comb at this point,
// maria-test will be used to do that. The idea is really to look for the totality of the
// router and how it will interact with the rest of the system.
// TO_REVIEW routeQuery() and clientReply() are the obvious functions to check for correctness.
// TO_REVIEW my use of mxs::QueryClassifier might be overly simple. The use should
// be as simple as possible, but no simpler.
// TODO, missing error handling. I did not add overly many asserts, which make reading code harder.
// But please note any that may be missing.
// TODO, for m_qc.target_is_all(), check that responses from all routers match.
// TODO Smart Query is not here yet, this is just a stupid router-router.
// COPY-PASTED error-extraction functions from rwsplit. TODO move to lib.
inline void extract_error_state(uint8_t* pBuffer, uint8_t** ppState, uint16_t* pnState)
{
@ -194,10 +176,13 @@ int SmartRouterSession::routeQuery(GWBUF* pBuf)
else
{
auto route_info = m_qc.update_route_info(mxs::QueryClassifier::CURRENT_TARGET_UNDEFINED, pBuf);
m_measurement = {maxbase::Clock::now(), maxscale::get_canonical(pBuf)};
if (m_qc.target_is_all(route_info.target()))
{
MXS_SDEBUG("Write all");
ret = write_to_all(pBuf);
ret = write_to_all(pBuf, Mode::Query);
}
else if (m_qc.target_is_master(route_info.target()) || session_trx_is_active(m_pClient_dcb->session))
{
@ -206,9 +191,25 @@ int SmartRouterSession::routeQuery(GWBUF* pBuf)
}
else
{
// TODO: This is where canonical performance data will be used, and measurements initiated
// Currently writing to all for clientReply testing purposes.
ret = write_to_all(pBuf);
std::string canonical = maxscale::get_canonical(pBuf);
auto perf = perf_find(canonical);
if (perf.is_valid())
{
MXS_SDEBUG("Route to " << perf.host() << " based on performance, canonical = "
<< show_some(canonical));
ret = write_to_host(perf.host(), pBuf);
}
else if (modutil_is_SQL(pBuf))
{
MXS_SDEBUG("Start measurement");
ret = write_to_all(pBuf, Mode::MeasureQuery);
}
else
{
MXS_SWARNING("Could not determine target (non-sql query), goes to master");
ret = write_to_master(pBuf);
}
}
}
@ -233,7 +234,7 @@ void SmartRouterSession::clientReply(GWBUF* pPacket, DCB* pDcb)
cluster.tracker.update_response(pPacket);
// these flags can all be true at the same time
bool first_response_packet = m_mode != Mode::CollectResults;
bool first_response_packet = (m_mode == Mode::Query || m_mode == Mode::MeasureQuery);
bool last_packet_for_this_cluster = !cluster.tracker.expecting_response_packets();
bool very_last_response_packet = !expecting_response_packets(); // last from all clusters
@ -278,10 +279,19 @@ void SmartRouterSession::clientReply(GWBUF* pPacket, DCB* pDcb)
if (first_response_packet)
{
MXS_SDEBUG("Host " << cluster.host << " will be responding to the client");
maxbase::Duration query_dur = maxbase::Clock::now() - m_measurement.start;
MXS_SDEBUG("Host " << cluster.host << " will be responding to the client. "
<< "First packet received in time " << query_dur);
cluster.is_replying_to_client = true;
m_mode = Mode::CollectResults;
will_reply = true; // tentatively, the packet might have to be delayed
if (m_mode == Mode::MeasureQuery)
{
perf_update(m_measurement.canonical, {cluster.host, query_dur});
// kill_all_others(cluster.host);
}
m_mode = Mode::CollectResults;
}
if (very_last_response_packet)
@ -291,7 +301,7 @@ void SmartRouterSession::clientReply(GWBUF* pPacket, DCB* pDcb)
mxb_assert(cluster.is_replying_to_client || m_pDelayed_packet);
if (m_pDelayed_packet)
{
MXS_SDEBUG("Picking up delayed packet, discarding response from" << cluster.host);
MXS_SDEBUG("Picking up delayed packet, discarding response from " << cluster.host);
gwbuf_free(pPacket);
pPacket = m_pDelayed_packet;
m_pDelayed_packet = nullptr;
@ -384,7 +394,7 @@ bool SmartRouterSession::write_to_host(const maxbase::Host& host, GWBUF* pBuf)
return cluster.pDcb->func.write(cluster.pDcb, pBuf);
}
bool SmartRouterSession::write_to_all(GWBUF* pBuf)
bool SmartRouterSession::write_to_all(GWBUF* pBuf, Mode mode)
{
for (auto it = begin(m_clusters); it != end(m_clusters); ++it)
{
@ -397,7 +407,7 @@ bool SmartRouterSession::write_to_all(GWBUF* pBuf)
if (expecting_response_packets())
{
m_mode = Mode::Query;
m_mode = mode;
}
return true; // TODO. What could possibly go wrong?
@ -425,6 +435,24 @@ bool SmartRouterSession::write_split_packets(GWBUF* pBuf)
return true; // TODO. What could possibly go wrong?
}
void SmartRouterSession::kill_all_others(const maxbase::Host& host)
{
MySQLProtocol* pProt = static_cast<MySQLProtocol*>(m_pClient_dcb->protocol);
uint64_t mysql_thread_id = pProt->thread_id;
for (Cluster& cluster : m_clusters)
{
if (cluster.host == host || !cluster.tracker.expecting_response_packets())
{
continue;
}
MXS_SDEBUG("Queue " << cluster.host << " mysql_thread_id=" << mysql_thread_id << " for kill");
mxs_mysql_execute_kill(cluster.pDcb->session, mysql_thread_id, KT_QUERY);
}
}
void SmartRouterSession::handleError(GWBUF* pPacket,
DCB* pProblem,
mxs_error_action_t action,