Cache the local server statistics object

By storing the server statistics object in side the session, the lookup
involved in getting a worker-local value is avoided. Since the lookup is
done multiple times for a single query, it is beneficial to store it in
the session.

As the worker-local value is never deleted, it is safe to store a
reference to it in the session. It is also never updated concurrently so
no atomic operations are necessary.
This commit is contained in:
Markus Mäkelä
2018-12-09 15:01:52 +02:00
parent 1fa3b133c7
commit 9adbd2f8f0
6 changed files with 19 additions and 14 deletions

View File

@ -107,9 +107,9 @@ const Stats& RWSplit::stats() const
return m_stats;
}
ServerStats& RWSplit::server_stats(SERVER* server)
SrvStatMap& RWSplit::local_server_stats()
{
return (*m_server_stats)[server];
return *m_server_stats;
}
maxscale::SrvStatMap RWSplit::all_server_stats() const

View File

@ -264,7 +264,7 @@ public:
const Config& config() const;
Stats& stats();
const Stats& stats() const;
ServerStats& server_stats(SERVER* server);
SrvStatMap& local_server_stats();
SrvStatMap all_server_stats() const;
int max_slave_count() const;

View File

@ -477,8 +477,8 @@ bool RWSplitSession::route_session_write(GWBUF* querybuf, uint8_t command, uint3
{
nsucc += 1;
mxb::atomic::add(&backend->server()->stats.packets, 1, mxb::atomic::RELAXED);
m_router->server_stats(backend->server()).total++;
m_router->server_stats(backend->server()).read++;
m_server_stats[backend->server()].total++;
m_server_stats[backend->server()].read++;
if (expecting_response)
{
@ -853,7 +853,7 @@ SRWBackend RWSplitSession::handle_slave_is_target(uint8_t cmd, uint32_t stmt_id)
if (target)
{
mxb::atomic::add(&m_router->stats().n_slave, 1, mxb::atomic::RELAXED);
m_router->server_stats(target->server()).read++;
m_server_stats[target->server()].read++;
mxb_assert(target->in_use() || target->can_connect());
}
else
@ -990,7 +990,7 @@ bool RWSplitSession::handle_master_is_target(SRWBackend* dest)
if (target && target == m_current_master)
{
mxb::atomic::add(&m_router->stats().n_master, 1, mxb::atomic::RELAXED);
m_router->server_stats(target->server()).write++;
m_server_stats[target->server()].write++;
}
else
{
@ -1170,7 +1170,7 @@ bool RWSplitSession::handle_got_target(GWBUF* querybuf, SRWBackend& target, bool
mxb::atomic::add(&m_router->stats().n_queries, 1, mxb::atomic::RELAXED);
mxb::atomic::add(&target->server()->stats.packets, 1, mxb::atomic::RELAXED);
m_router->server_stats(target->server()).total++;
m_server_stats[target->server()].total++;
if (!m_qc.large_query() && response == mxs::Backend::EXPECT_RESPONSE)
{

View File

@ -45,6 +45,7 @@ RWSplitSession::RWSplitSession(RWSplit* instance,
, m_retry_duration(0)
, m_is_replay_active(false)
, m_can_replay_trx(true)
, m_server_stats(instance->local_server_stats())
{
if (m_config.rw_max_slave_conn_percent)
{
@ -84,7 +85,7 @@ RWSplitSession* RWSplitSession::create(RWSplit* router, MXS_SESSION* session)
for (auto& b : backends)
{
router->server_stats(b->server()).start_session();
rses->m_server_stats[b->server()].start_session();
}
}
}
@ -122,9 +123,9 @@ void RWSplitSession::close()
}
backend->response_stat().reset();
m_router->server_stats(backend->server()).end_session(backend->session_timer().split(),
backend->select_timer().total(),
backend->num_selects());
m_server_stats[backend->server()].end_session(backend->session_timer().split(),
backend->select_timer().total(),
backend->num_selects());
}
}

View File

@ -169,6 +169,10 @@ public:
otrx_state m_otrx_state = OTRX_INACTIVE; /**< Optimistic trx state*/
SrvStatMap& m_server_stats; /**< The server stats local to this thread, cached in the session object.
* This avoids the lookup involved in getting the worker-local value from
* the worker's container.*/
private:
RWSplitSession(RWSplit* instance,
MXS_SESSION* session,