hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
2aeed3ffabf59d121991d50bfd74e626872b5210
MaxScale/server/core/session.cc
Johan Wikman 3d45d452eb MXS-1734 Add possibility to instruct when to dump statements 
With the configuration entry

dump_last_statements=[never|on_close|on_error]

you can now specify when and if to dump the last statements
of of a session.
2018-03-27 09:35:35 +03:00

1210 lines
34 KiB
C++
Raw Blame History

/*
* 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.
*/
/**
* @file session.c - A representation of the session within the gateway.
*/
#include <maxscale/session.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <string>
#include <sstream>
#include <maxscale/alloc.h>
#include <maxscale/atomic.h>
#include <maxscale/dcb.h>
#include <maxscale/housekeeper.h>
#include <maxscale/log_manager.h>
#include <maxscale/poll.h>
#include <maxscale/router.h>
#include <maxscale/service.h>
#include <maxscale/spinlock.h>
#include <maxscale/utils.h>
#include <maxscale/json_api.h>
#include <maxscale/protocol/mysql.h>
#include "internal/dcb.h"
#include "internal/session.h"
#include "internal/filter.h"
#include "internal/worker.hh"
#include "internal/workertask.hh"
using std::string;
using std::stringstream;
/** Global session id counter. Must be updated atomically. Value 0 is reserved for
* dummy/unused sessions.
*/
static uint64_t next_session_id = 1;
static uint32_t retain_last_statements = 0;
static session_dump_statements_t dump_statements = SESSION_DUMP_STATEMENTS_NEVER;
static struct session session_dummy_struct;
static void session_initialize(void *session);
static int session_setup_filters(MXS_SESSION *session);
static void session_simple_free(MXS_SESSION *session, DCB *dcb);
static void session_add_to_all_list(MXS_SESSION *session);
static MXS_SESSION *session_find_free();
static void session_final_free(MXS_SESSION *session);
static MXS_SESSION* session_alloc_body(SERVICE* service, DCB* client_dcb,
MXS_SESSION* session);
/**
* The clientReply of the session.
*
* @param inst In reality an MXS_SESSION*.
* @param session In reality an MXS_SESSION*.
* @param data The data to send to the client.
*/
static int session_reply(MXS_FILTER *inst, MXS_FILTER_SESSION *session, GWBUF *data);
/**
* @brief Initialize a session
*
* This routine puts initial values into the fields of the session pointed to
* by the parameter.
*
* @param *session Pointer to the session to be initialized
*/
static void
session_initialize(MXS_SESSION *session)
{
memset(session, 0, sizeof(MXS_SESSION));
session->ses_chk_top = CHK_NUM_SESSION;
session->state = SESSION_STATE_ALLOC;
session->last_statements = new SessionStmtQueue;
session->ses_chk_tail = CHK_NUM_SESSION;
}
MXS_SESSION* session_alloc(SERVICE *service, DCB *client_dcb)
{
MXS_SESSION *session = (MXS_SESSION *)(MXS_MALLOC(sizeof(*session)));
if (NULL == session)
{
return NULL;
}
session_initialize(session);
session->ses_id = session_get_next_id();
return session_alloc_body(service, client_dcb, session);
}
MXS_SESSION* session_alloc_with_id(SERVICE *service, DCB *client_dcb, uint64_t id)
{
MXS_SESSION *session = (MXS_SESSION *)(MXS_MALLOC(sizeof(*session)));
if (session == NULL)
{
return NULL;
}
session_initialize(session);
session->ses_id = id;
return session_alloc_body(service, client_dcb, session);
}
static MXS_SESSION* session_alloc_body(SERVICE* service, DCB* client_dcb,
MXS_SESSION* session)
{
session->service = service;
session->client_dcb = client_dcb;
session->stats.connect = time(0);
session->stmt.buffer = NULL;
session->stmt.target = NULL;
session->qualifies_for_pooling = false;
MXS_CONFIG *config = config_get_global_options();
// If MaxScale is running in Oracle mode, then autocommit needs to
// initially be off.
bool autocommit = (config->qc_sql_mode == QC_SQL_MODE_ORACLE) ? false : true;
session_set_autocommit(session, autocommit);
/*<
* Associate the session to the client DCB and set the reference count on
* the session to indicate that there is a single reference to the
* session. There is no need to protect this or use atomic add as the
* session has not been made available to the other threads at this
* point.
*/
session->refcount = 1;
/*<
* This indicates that session is ready to be shared with backend
* DCBs. Note that this doesn't mean that router is initialized yet!
*/
session->state = SESSION_STATE_READY;
session->trx_state = SESSION_TRX_INACTIVE;
session->autocommit = true;
/*
* Only create a router session if we are not the listening DCB or an
* internal DCB. Creating a router session may create a connection to
* a backend server, depending upon the router module implementation
* and should be avoided for a listener session.
*
* Router session creation may create other DCBs that link to the
* session.
*/
if (client_dcb->state != DCB_STATE_LISTENING &&
client_dcb->dcb_role != DCB_ROLE_INTERNAL)
{
session->router_session = service->router->newSession(service->router_instance, session);
if (session->router_session == NULL)
{
session->state = SESSION_STATE_TO_BE_FREED;
MXS_ERROR("Failed to create new router session for service '%s'. "
"See previous errors for more details.", service->name);
}
/*
* Pending filter chain being setup set the head of the chain to
* be the router. As filters are inserted the current head will
* be pushed to the filter and the head updated.
*
* NB This dictates that filters are created starting at the end
* of the chain nearest the router working back to the client
* protocol end of the chain.
*/
// NOTE: Here we cast the router instance into a MXS_FILTER and
// NOTE: the router session into a MXS_FILTER_SESSION and
// NOTE: the router routeQuery into a filter routeQuery. That
// NOTE: is in order to be able to treat the router as the first
// NOTE: filter.
session->head.instance = (MXS_FILTER*)service->router_instance;
session->head.session = (MXS_FILTER_SESSION*)session->router_session;
session->head.routeQuery =
(int32_t (*)(MXS_FILTER*, MXS_FILTER_SESSION*, GWBUF*))service->router->routeQuery;
// NOTE: Here we cast the session into a MXS_FILTER and MXS_FILTER_SESSION
// NOTE: and session_reply into a filter clientReply. That's dubious but ok
// NOTE: as session_reply will know what to do. In practice, the session
// NOTE: will be called as if it would be the last filter.
session->tail.instance = (MXS_FILTER*)session;
session->tail.session = (MXS_FILTER_SESSION*)session;
session->tail.clientReply = session_reply;
if (SESSION_STATE_TO_BE_FREED != session->state
&& service->n_filters > 0
&& !session_setup_filters(session))
{
session->state = SESSION_STATE_TO_BE_FREED;
MXS_ERROR("Setting up filters failed. "
"Terminating session %s.",
service->name);
}
}
if (SESSION_STATE_TO_BE_FREED != session->state)
{
session->state = SESSION_STATE_ROUTER_READY;
if (session->client_dcb->user == NULL)
{
MXS_INFO("Started session [%" PRIu64 "] for %s service ",
session->ses_id,
service->name);
}
else
{
MXS_INFO("Started %s client session [%" PRIu64 "] for '%s' from %s",
service->name,
session->ses_id,
session->client_dcb->user,
session->client_dcb->remote);
}
}
else
{
MXS_INFO("Start %s client session [%" PRIu64 "] for '%s' from %s failed, will be "
"closed as soon as all related DCBs have been closed.",
service->name,
session->ses_id,
session->client_dcb->user,
session->client_dcb->remote);
}
atomic_add(&service->stats.n_sessions, 1);
atomic_add(&service->stats.n_current, 1);
CHK_SESSION(session);
client_dcb->session = session;
return (session->state == SESSION_STATE_TO_BE_FREED) ? NULL : session;
}
/**
* Allocate a dummy session so that DCBs can always have sessions.
*
* Only one dummy session exists, it is statically declared
*
* @param client_dcb The client side DCB
* @return The dummy created session
*/
MXS_SESSION *
session_set_dummy(DCB *client_dcb)
{
MXS_SESSION *session;
session = &session_dummy_struct;
session->ses_chk_top = CHK_NUM_SESSION;
session->ses_chk_tail = CHK_NUM_SESSION;
session->service = NULL;
session->client_dcb = NULL;
session->n_filters = 0;
memset(&session->stats, 0, sizeof(MXS_SESSION_STATS));
session->stats.connect = 0;
session->state = SESSION_STATE_DUMMY;
session->refcount = 1;
session->ses_id = 0;
client_dcb->session = session;
return session;
}
void session_link_backend_dcb(MXS_SESSION *session, DCB *dcb)
{
ss_dassert(dcb->dcb_role == DCB_ROLE_BACKEND_HANDLER);
atomic_add(&session->refcount, 1);
dcb->session = session;
dcb->service = session->service;
/** Move this DCB under the same thread */
dcb->poll.thread.id = session->client_dcb->poll.thread.id;
}
/**
* Deallocate the specified session, minimal actions during session_alloc
* Since changes to keep new session in existence until all related DCBs
* have been destroyed, this function is redundant. Just left until we are
* sure of the direction taken.
*
* @param session The session to deallocate
*/
static void
session_simple_free(MXS_SESSION *session, DCB *dcb)
{
/* Does this possibly need a lock? */
if (dcb->data)
{
void * clientdata = dcb->data;
dcb->data = NULL;
MXS_FREE(clientdata);
}
if (session)
{
if (SESSION_STATE_DUMMY == session->state)
{
return;
}
if (session && session->router_session)
{
session->service->router->freeSession(
session->service->router_instance,
session->router_session);
}
session->state = SESSION_STATE_STOPPING;
}
session_final_free(session);
}
void session_close(MXS_SESSION *session)
{
if (session->router_session)
{
session->state = SESSION_STATE_STOPPING;
MXS_ROUTER_OBJECT* router = session->service->router;
MXS_ROUTER* router_instance = session->service->router_instance;
/** Close router session and all its connections */
router->closeSession(router_instance, session->router_session);
}
}
/**
* Deallocate the specified session
*
* @param session The session to deallocate
*/
static void session_free(MXS_SESSION *session)
{
CHK_SESSION(session);
ss_dassert(session->refcount == 0);
session->state = SESSION_STATE_TO_BE_FREED;
atomic_add(&session->service->stats.n_current, -1);
if (session->client_dcb)
{
dcb_free_all_memory(session->client_dcb);
session->client_dcb = NULL;
}
/**
* If session is not child of some other session, free router_session.
* Otherwise let the parent free it.
*/
if (session->router_session)
{
session->service->router->freeSession(session->service->router_instance,
session->router_session);
}
if (session->n_filters)
{
int i;
for (i = 0; i < session->n_filters; i++)
{
if (session->filters[i].filter)
{
session->filters[i].filter->obj->closeSession(session->filters[i].instance,
session->filters[i].session);
}
}
for (i = 0; i < session->n_filters; i++)
{
if (session->filters[i].filter)
{
session->filters[i].filter->obj->freeSession(session->filters[i].instance,
session->filters[i].session);
}
}
MXS_FREE(session->filters);
}
MXS_INFO("Stopped %s client session [%" PRIu64 "]", session->service->name, session->ses_id);
session->state = SESSION_STATE_FREE;
session_final_free(session);
}
static void
session_final_free(MXS_SESSION *session)
{
if (dump_statements == SESSION_DUMP_STATEMENTS_ON_CLOSE)
{
session_dump_statements(session);
}
gwbuf_free(session->stmt.buffer);
delete session->last_statements;
MXS_FREE(session);
}
/**
* Check to see if a session is valid, i.e. in the list of all sessions
*
* @param session Session to check
* @return 1 if the session is valid otherwise 0
*/
int
session_isvalid(MXS_SESSION *session)
{
return session != NULL;
}
/**
* Print details of an individual session
*
* @param session Session to print
*/
void
printSession(MXS_SESSION *session)
{
struct tm result;
char timebuf[40];
printf("Session %p\n", session);
printf("\tState: %s\n", session_state(session->state));
printf("\tService: %s (%p)\n", session->service->name, session->service);
printf("\tClient DCB: %p\n", session->client_dcb);
printf("\tConnected: %s\n",
asctime_r(localtime_r(&session->stats.connect, &result), timebuf));
printf("\tRouter Session: %p\n", session->router_session);
}
bool printAllSessions_cb(DCB *dcb, void *data)
{
if (dcb->dcb_role == DCB_ROLE_CLIENT_HANDLER)
{
printSession(dcb->session);
}
return true;
}
/**
* Print all sessions
*
* Designed to be called within a debugger session in order
* to display all active sessions within the gateway
*/
void
printAllSessions()
{
dcb_foreach(printAllSessions_cb, NULL);
}
/** Callback for dprintAllSessions */
bool dprintAllSessions_cb(DCB *dcb, void *data)
{
if (dcb->dcb_role == DCB_ROLE_CLIENT_HANDLER &&
dcb->session->state != SESSION_STATE_DUMMY)
{
DCB *out_dcb = (DCB*)data;
dprintSession(out_dcb, dcb->session);
}
return true;
}
/**
* Print all sessions to a DCB
*
* Designed to be called within a debugger session in order
* to display all active sessions within the gateway
*
* @param dcb The DCB to print to
*/
void
dprintAllSessions(DCB *dcb)
{
dcb_foreach(dprintAllSessions_cb, dcb);
}
/**
* Print a particular session to a DCB
*
* Designed to be called within a debugger session in order
* to display all active sessions within the gateway
*
* @param dcb The DCB to print to
* @param print_session The session to print
*/
void
dprintSession(DCB *dcb, MXS_SESSION *print_session)
{
struct tm result;
char buf[30];
int i;
dcb_printf(dcb, "Session %" PRIu64 "\n", print_session->ses_id);
dcb_printf(dcb, "\tState: %s\n", session_state(print_session->state));
dcb_printf(dcb, "\tService: %s\n", print_session->service->name);
if (print_session->client_dcb && print_session->client_dcb->remote)
{
double idle = (hkheartbeat - print_session->client_dcb->last_read);
idle = idle > 0 ? idle / 10.f : 0;
dcb_printf(dcb, "\tClient Address: %s%s%s\n",
print_session->client_dcb->user ? print_session->client_dcb->user : "",
print_session->client_dcb->user ? "@" : "",
print_session->client_dcb->remote);
dcb_printf(dcb, "\tConnected: %s\n",
asctime_r(localtime_r(&print_session->stats.connect, &result), buf));
if (print_session->client_dcb->state == DCB_STATE_POLLING)
{
dcb_printf(dcb, "\tIdle: %.0f seconds\n", idle);
}
}
if (print_session->n_filters)
{
for (i = 0; i < print_session->n_filters; i++)
{
dcb_printf(dcb, "\tFilter: %s\n",
print_session->filters[i].filter->name);
print_session->filters[i].filter->obj->diagnostics(print_session->filters[i].instance,
print_session->filters[i].session,
dcb);
}
}
}
bool dListSessions_cb(DCB *dcb, void *data)
{
if (dcb->dcb_role == DCB_ROLE_CLIENT_HANDLER)
{
DCB *out_dcb = (DCB*)data;
MXS_SESSION *session = dcb->session;
dcb_printf(out_dcb, "%-16" PRIu64 " | %-15s | %-14s | %s\n", session->ses_id,
session->client_dcb && session->client_dcb->remote ?
session->client_dcb->remote : "",
session->service && session->service->name ?
session->service->name : "",
session_state(session->state));
}
return true;
}
/**
* List all sessions in tabular form to a DCB
*
* Designed to be called within a debugger session in order
* to display all active sessions within the gateway
*
* @param dcb The DCB to print to
*/
void
dListSessions(DCB *dcb)
{
dcb_printf(dcb, "-----------------+-----------------+----------------+--------------------------\n");
dcb_printf(dcb, "Session | Client | Service | State\n");
dcb_printf(dcb, "-----------------+-----------------+----------------+--------------------------\n");
dcb_foreach(dListSessions_cb, dcb);
dcb_printf(dcb, "-----------------+-----------------+----------------+--------------------------\n\n");
}
/**
* Convert a session state to a string representation
*
* @param state The session state
* @return A string representation of the session state
*/
const char *
session_state(mxs_session_state_t state)
{
switch (state)
{
case SESSION_STATE_ALLOC:
return "Session Allocated";
case SESSION_STATE_DUMMY:
return "Dummy Session";
case SESSION_STATE_READY:
return "Session Ready";
case SESSION_STATE_ROUTER_READY:
return "Session ready for routing";
case SESSION_STATE_LISTENER:
return "Listener Session";
case SESSION_STATE_LISTENER_STOPPED:
return "Stopped Listener Session";
case SESSION_STATE_STOPPING:
return "Stopping session";
case SESSION_STATE_TO_BE_FREED:
return "Session to be freed";
case SESSION_STATE_FREE:
return "Freed session";
default:
return "Invalid State";
}
}
/**
* Create the filter chain for this session.
*
* Filters must be setup in reverse order, starting with the last
* filter in the chain and working back towards the client connection
* Each filter is passed the current session head of the filter chain
* this head becomes the destination for the filter. The newly created
* filter becomes the new head of the filter chain.
*
* @param session The session that requires the chain
* @return 0 if filter creation fails
*/
static int
session_setup_filters(MXS_SESSION *session)
{
SERVICE *service = session->service;
MXS_DOWNSTREAM *head;
MXS_UPSTREAM *tail;
int i;
if ((session->filters = (SESSION_FILTER*)MXS_CALLOC(service->n_filters,
sizeof(SESSION_FILTER))) == NULL)
{
return 0;
}
session->n_filters = service->n_filters;
for (i = service->n_filters - 1; i >= 0; i--)
{
if (service->filters[i] == NULL)
{
MXS_ERROR("Service '%s' contians an unresolved filter.", service->name);
return 0;
}
if ((head = filter_apply(service->filters[i], session,
&session->head)) == NULL)
{
MXS_ERROR("Failed to create filter '%s' for "
"service '%s'.\n",
service->filters[i]->name,
service->name);
return 0;
}
session->filters[i].filter = service->filters[i];
session->filters[i].session = head->session;
session->filters[i].instance = head->instance;
session->head = *head;
MXS_FREE(head);
}
for (i = 0; i < service->n_filters; i++)
{
if ((tail = filter_upstream(service->filters[i],
session->filters[i].session,
&session->tail)) == NULL)
{
MXS_ERROR("Failed to create filter '%s' for service '%s'.",
service->filters[i]->name,
service->name);
return 0;
}
/*
* filter_upstream may simply return the 3 parameter if
* the filter has no upstream entry point. So no need
* to copy the contents or free tail in this case.
*/
if (tail != &session->tail)
{
session->tail = *tail;
MXS_FREE(tail);
}
}
return 1;
}
/**
* Entry point for the final element in the upstream filter, i.e. the writing
* of the data to the client.
*
* Looks like a filter `clientReply`, but in this case both the instance and
* the session argument will be a MXS_SESSION*.
*
* @param instance The "instance" data
* @param session The session
* @param data The buffer chain to write
*/
int
session_reply(MXS_FILTER *instance, MXS_FILTER_SESSION *session, GWBUF *data)
{
MXS_SESSION *the_session = (MXS_SESSION*)session;
return the_session->client_dcb->func.write(the_session->client_dcb, data);
}
/**
* Return the client connection address or name
*
* @param session The session whose client address to return
*/
const char *
session_get_remote(const MXS_SESSION *session)
{
if (session && session->client_dcb)
{
return session->client_dcb->remote;
}
return NULL;
}
bool session_route_query(MXS_SESSION* ses, GWBUF* buf)
{
bool succp;
if (ses->head.routeQuery == NULL ||
ses->head.instance == NULL ||
ses->head.session == NULL)
{
succp = false;
goto return_succp;
}
if (ses->head.routeQuery(ses->head.instance, ses->head.session, buf) == 1)
{
succp = true;
}
else
{
succp = false;
}
return_succp:
return succp;
}
/**
* Return the username of the user connected to the client side of the
* session.
*
* @param session The session pointer.
* @return The user name or NULL if it can not be determined.
*/
const char *
session_get_user(const MXS_SESSION *session)
{
return (session && session->client_dcb) ? session->client_dcb->user : NULL;
}
/**
* Callback structure for the session list extraction
*/
typedef struct
{
int index;
int current;
SESSIONLISTFILTER filter;
RESULT_ROW *row;
RESULTSET *set;
} SESSIONFILTER;
bool dcb_iter_cb(DCB *dcb, void *data)
{
SESSIONFILTER *cbdata = (SESSIONFILTER*)data;
if (cbdata->current < cbdata->index)
{
if (cbdata->filter == SESSION_LIST_ALL ||
(cbdata->filter == SESSION_LIST_CONNECTION &&
(dcb->session->state != SESSION_STATE_LISTENER)))
{
cbdata->current++;
}
}
else
{
char buf[20];
MXS_SESSION *list_session = dcb->session;
cbdata->index++;
cbdata->row = resultset_make_row(cbdata->set);
snprintf(buf, sizeof(buf), "%p", list_session);
resultset_row_set(cbdata->row, 0, buf);
resultset_row_set(cbdata->row, 1, ((list_session->client_dcb && list_session->client_dcb->remote)
? list_session->client_dcb->remote : ""));
resultset_row_set(cbdata->row, 2, (list_session->service && list_session->service->name
? list_session->service->name : ""));
resultset_row_set(cbdata->row, 3, session_state(list_session->state));
return false;
}
return true;
}
/**
* Provide a row to the result set that defines the set of sessions
*
* @param set The result set
* @param data The index of the row to send
* @return The next row or NULL
*/
static RESULT_ROW *
sessionRowCallback(RESULTSET *set, void *data)
{
SESSIONFILTER *cbdata = (SESSIONFILTER*)data;
RESULT_ROW *row = NULL;
cbdata->current = 0;
dcb_foreach(dcb_iter_cb, cbdata);
if (cbdata->row)
{
row = cbdata->row;
cbdata->row = NULL;
}
return row;
}
/**
* Return a resultset that has the current set of sessions in it
*
* @return A Result set
*/
/* Lint is not convinced that the new memory for data is always tracked
* because it does not see what happens within the resultset_create function,
* so we suppress the warning. In fact, the function call results in return
* of the set structure which includes a pointer to data
*/
/*lint -e429 */
RESULTSET *
sessionGetList(SESSIONLISTFILTER filter)
{
RESULTSET *set;
SESSIONFILTER *data;
if ((data = (SESSIONFILTER *)MXS_MALLOC(sizeof(SESSIONFILTER))) == NULL)
{
return NULL;
}
data->index = 0;
data->filter = filter;
data->current = 0;
data->row = NULL;
if ((set = resultset_create(sessionRowCallback, data)) == NULL)
{
MXS_FREE(data);
return NULL;
}
data->set = set;
resultset_add_column(set, "Session", 16, COL_TYPE_VARCHAR);
resultset_add_column(set, "Client", 15, COL_TYPE_VARCHAR);
resultset_add_column(set, "Service", 15, COL_TYPE_VARCHAR);
resultset_add_column(set, "State", 15, COL_TYPE_VARCHAR);
return set;
}
/*lint +e429 */
mxs_session_trx_state_t session_get_trx_state(const MXS_SESSION* ses)
{
return ses->trx_state;
}
mxs_session_trx_state_t session_set_trx_state(MXS_SESSION* ses, mxs_session_trx_state_t new_state)
{
mxs_session_trx_state_t prev_state = ses->trx_state;
ses->trx_state = new_state;
return prev_state;
}
const char* session_trx_state_to_string(mxs_session_trx_state_t state)
{
switch (state)
{
case SESSION_TRX_INACTIVE:
return "SESSION_TRX_INACTIVE";
case SESSION_TRX_ACTIVE:
return "SESSION_TRX_ACTIVE";
case SESSION_TRX_READ_ONLY:
return "SESSION_TRX_READ_ONLY";
case SESSION_TRX_READ_WRITE:
return "SESSION_TRX_READ_WRITE";
case SESSION_TRX_READ_ONLY_ENDING:
return "SESSION_TRX_READ_ONLY_ENDING";
case SESSION_TRX_READ_WRITE_ENDING:
return "SESSION_TRX_READ_WRITE_ENDING";
}
MXS_ERROR("Unknown session_trx_state_t value: %d", (int)state);
return "UNKNOWN";
}
static bool ses_find_id(DCB *dcb, void *data)
{
void **params = (void**)data;
MXS_SESSION **ses = (MXS_SESSION**)params[0];
uint64_t *id = (uint64_t*)params[1];
bool rval = true;
if (dcb->session->ses_id == *id)
{
*ses = session_get_ref(dcb->session);
rval = false;
}
return rval;
}
MXS_SESSION* session_get_by_id(uint64_t id)
{
MXS_SESSION *session = NULL;
void *params[] = {&session, &id};
dcb_foreach(ses_find_id, params);
return session;
}
MXS_SESSION* session_get_ref(MXS_SESSION *session)
{
atomic_add(&session->refcount, 1);
return session;
}
void session_put_ref(MXS_SESSION *session)
{
if (session && session->state != SESSION_STATE_DUMMY)
{
/** Remove one reference. If there are no references left, free session */
if (atomic_add(&session->refcount, -1) == 1)
{
session_free(session);
}
}
}
bool session_store_stmt(MXS_SESSION *session, GWBUF *buf, const SERVER *server)
{
bool rval = false;
if (session->stmt.buffer)
{
/** This should not happen with proper use */
ss_dassert(false);
gwbuf_free(session->stmt.buffer);
}
if ((session->stmt.buffer = gwbuf_clone(buf)))
{
session->stmt.target = server;
/** No old statements were stored and we successfully cloned the buffer */
rval = true;
}
return rval;
}
bool session_take_stmt(MXS_SESSION *session, GWBUF **buffer, const SERVER **target)
{
bool rval = false;
if (session->stmt.buffer && session->stmt.target)
{
*buffer = session->stmt.buffer;
*target = session->stmt.target;
session->stmt.buffer = NULL;
session->stmt.target = NULL;
rval = true;
}
return rval;
}
void session_clear_stmt(MXS_SESSION *session)
{
gwbuf_free(session->stmt.buffer);
session->stmt.buffer = NULL;
session->stmt.target = NULL;
}
uint64_t session_get_next_id()
{
return atomic_add_uint64(&next_session_id, 1);
}
json_t* session_json_data(const MXS_SESSION *session, const char *host)
{
json_t* data = json_object();
/** ID must be a string */
stringstream ss;
ss << session->ses_id;
/** ID and type */
json_object_set_new(data, CN_ID, json_string(ss.str().c_str()));
json_object_set_new(data, CN_TYPE, json_string(CN_SESSIONS));
/** Relationships */
json_t* rel = json_object();
/** Service relationship (one-to-one) */
json_t* services = mxs_json_relationship(host, MXS_JSON_API_SERVICES);
mxs_json_add_relation(services, session->service->name, CN_SERVICES);
json_object_set_new(rel, CN_SERVICES, services);
/** Filter relationships (one-to-many) */
if (session->n_filters)
{
json_t* filters = mxs_json_relationship(host, MXS_JSON_API_FILTERS);
for (int i = 0; i < session->n_filters; i++)
{
mxs_json_add_relation(filters, session->filters[i].filter->name, CN_FILTERS);
}
json_object_set_new(rel, CN_FILTERS, filters);
}
json_object_set_new(data, CN_RELATIONSHIPS, rel);
/** Session attributes */
json_t* attr = json_object();
json_object_set_new(attr, "state", json_string(session_state(session->state)));
if (session->client_dcb->user)
{
json_object_set_new(attr, CN_USER, json_string(session->client_dcb->user));
}
if (session->client_dcb->remote)
{
json_object_set_new(attr, "remote", json_string(session->client_dcb->remote));
}
struct tm result;
char buf[60];
asctime_r(localtime_r(&session->stats.connect, &result), buf);
trim(buf);
json_object_set_new(attr, "connected", json_string(buf));
if (session->client_dcb->state == DCB_STATE_POLLING)
{
double idle = (hkheartbeat - session->client_dcb->last_read);
idle = idle > 0 ? idle / 10.f : 0;
json_object_set_new(attr, "idle", json_real(idle));
}
json_object_set_new(data, CN_ATTRIBUTES, attr);
json_object_set_new(data, CN_LINKS, mxs_json_self_link(host, CN_SESSIONS, ss.str().c_str()));
return data;
}
json_t* session_to_json(const MXS_SESSION *session, const char *host)
{
stringstream ss;
ss << MXS_JSON_API_SESSIONS << session->ses_id;
return mxs_json_resource(host, ss.str().c_str(), session_json_data(session, host));
}
struct SessionListData
{
json_t* json;
const char* host;
};
bool seslist_cb(DCB* dcb, void* data)
{
if (dcb->dcb_role == DCB_ROLE_CLIENT_HANDLER)
{
SessionListData* d = (SessionListData*)data;
json_array_append_new(d->json, session_json_data(dcb->session, d->host));
}
return true;
}
json_t* session_list_to_json(const char* host)
{
SessionListData data = {json_array(), host};
dcb_foreach(seslist_cb, &data);
return mxs_json_resource(host, MXS_JSON_API_SESSIONS, data.json);
}
void session_qualify_for_pool(MXS_SESSION* session)
{
session->qualifies_for_pooling = true;
}
bool session_valid_for_pool(const MXS_SESSION* session)
{
ss_dassert(session->state != SESSION_STATE_DUMMY);
return session->qualifies_for_pooling;
}
MXS_SESSION* session_get_current()
{
DCB* dcb = dcb_get_current();
return dcb ? dcb->session : NULL;
}
uint64_t session_get_current_id()
{
MXS_SESSION* session = session_get_current();
return session ? session->ses_id : 0;
}
void session_set_retain_last_statements(uint32_t n)
{
retain_last_statements = n;
}
void session_set_dump_statements(session_dump_statements_t value)
{
dump_statements = value;
}
session_dump_statements_t session_get_dump_statements()
{
return dump_statements;
}
void session_retain_statement(MXS_SESSION* pSession, GWBUF* pBuffer)
{
if (retain_last_statements)
{
size_t len = gwbuf_length(pBuffer);
if (len > MYSQL_HEADER_LEN)
{
uint8_t header[MYSQL_HEADER_LEN + 1];
uint8_t* pHeader = NULL;
if (GWBUF_LENGTH(pBuffer) > MYSQL_HEADER_LEN)
{
pHeader = GWBUF_DATA(pBuffer);
}
else
{
gwbuf_copy_data(pBuffer, 0, MYSQL_HEADER_LEN + 1, header);
pHeader = header;
}
if (MYSQL_GET_COMMAND(pHeader) == MXS_COM_QUERY)
{
ss_dassert(pSession->last_statements->size() <= retain_last_statements);
if (pSession->last_statements->size() == retain_last_statements)
{
pSession->last_statements->pop_back();
}
std::vector<uint8_t> stmt(len - MYSQL_HEADER_LEN - 1);
gwbuf_copy_data(pBuffer, MYSQL_HEADER_LEN + 1, len - (MYSQL_HEADER_LEN + 1), &stmt.front());
pSession->last_statements->push_front(stmt);
}
}
}
}
void session_dump_statements(MXS_SESSION* pSession)
{
if (retain_last_statements)
{
int n = pSession->last_statements->size();
uint64_t id = session_get_current_id();
if ((id != 0) && (id != pSession->ses_id))
{
MXS_WARNING("Current session is %" PRIu64 ", yet statements are dumped for %" PRIu64 ". "
"The session id in the subsequent dumped statements is the wrong one.",
id, pSession->ses_id);
}
for (auto i = pSession->last_statements->rbegin(); i != pSession->last_statements->rend(); ++i)
{
int len = i->size();
const char* pStmt = (char*) &i->front();
if (id != 0)
{
MXS_NOTICE("Stmt %d: %.*s", n, len, pStmt);
}
else
{
// We are in a context where we do not have a current session, so we need to
// log the session id ourselves.
MXS_NOTICE("(%" PRIu64 ") Stmt %d: %.*s", pSession->ses_id, n, len, pStmt);
}
--n;
}
}
}
Reference in New Issue View Git Blame Copy Permalink