/**

* Copyright (c) 2021 OceanBase

* OceanBase CE is licensed under Mulan PubL v2.

* You can use this software according to the terms and conditions of the Mulan PubL v2.

* You may obtain a copy of Mulan PubL v2 at:

* http://license.coscl.org.cn/MulanPubL-2.0

* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,

* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,

* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.

* See the Mulan PubL v2 for more details.

*/

#define USING_LOG_PREFIX SQL

#include "sql/session/ob_sql_session_mgr.h"

#include "lib/string/ob_sql_string.h"

#include "lib/stat/ob_session_stat.h"

#include "lib/mysqlclient/ob_mysql_proxy.h"

#include "lib/utility/ob_tracepoint.h"

#include "share/inner_table/ob_inner_table_schema_constants.h"

#include "share/ob_resource_limit.h"

#include "io/easy_io.h"

#include "rpc/ob_rpc_define.h"

#include "sql/ob_sql_trans_control.h"

#include "observer/mysql/obsm_handler.h"

#include "rpc/obmysql/obsm_struct.h"

#include "observer/ob_server_struct.h"

#include "sql/monitor/ob_security_audit_utils.h"

#include "sql/session/ob_user_resource_mgr.h"

#include "sql/monitor/flt/ob_flt_control_info_mgr.h"

#include "storage/concurrency_control/ob_multi_version_garbage_collector.h"

using namespace oceanbase::common;

using namespace oceanbase::sql;

using namespace oceanbase::share;

using namespace oceanbase::observer;

ObTenantSQLSessionMgr::SessionPool::SessionPool()

: session_pool_()

{

MEMSET(session_array_, 0, POOL_CAPACIPY * sizeof(ObSQLSessionInfo *));

}

int ObTenantSQLSessionMgr::SessionPool::init(const int64_t capacity)

{

int ret = OB_SUCCESS;

int64_t real_cap = capacity;

if (real_cap > POOL_CAPACIPY) {

real_cap = POOL_CAPACIPY;

}

char *session_buf = reinterpret_cast<char *>(session_array_);

OZ (session_pool_.init(real_cap, session_buf));

return ret;

}

int ObTenantSQLSessionMgr::SessionPool::pop_session(ObSQLSessionInfo *&session)

{

int ret = OB_SUCCESS;

session = NULL;

if (OB_FAIL(session_pool_.pop(session))) {

if (ret != OB_ENTRY_NOT_EXIST) {

LOG_WARN("failed to pop session", K(ret),

K(session_pool_.get_total()), K(session_pool_.get_free()));

} else {

ret = OB_SUCCESS;

LOG_DEBUG("session pool is empty",

K(session_pool_.get_total()), K(session_pool_.get_free()));

}

}

return ret;

}

int ObTenantSQLSessionMgr::SessionPool::push_session(ObSQLSessionInfo *&session)

{

int ret = OB_SUCCESS;

if (OB_NOT_NULL(session)) {

if (OB_FAIL(session_pool_.push(session))) {

if (ret != OB_SIZE_OVERFLOW) {

LOG_WARN("failed to push session", K(ret),

K(session_pool_.get_total()), K(session_pool_.get_free()));

} else {

ret = OB_SUCCESS;

LOG_DEBUG("session pool is full",

K(session_pool_.get_total()), K(session_pool_.get_free()));

}

} else {

session = NULL;

}

}

return ret;

}

int64_t ObTenantSQLSessionMgr::SessionPool::count() const

{

return session_pool_.get_total();

}

ObTenantSQLSessionMgr::ObTenantSQLSessionMgr(const int64_t tenant_id)

: tenant_id_(tenant_id),

session_allocator_(lib::ObMemAttr(tenant_id, "SQLSessionInfo"), MTL_CPU_COUNT(), 4)

{}

ObTenantSQLSessionMgr::~ObTenantSQLSessionMgr()

{}

int ObTenantSQLSessionMgr::init()

{

int ret = OB_SUCCESS;

if (OB_FAIL(session_pool_.init(SessionPool::POOL_CAPACIPY))) {

LOG_WARN("fail to init session pool", K(tenant_id_), K(ret));

}

return ret;

}

void ObTenantSQLSessionMgr::destroy()

{

}

int ObTenantSQLSessionMgr::mtl_init(ObTenantSQLSessionMgr *&t_session_mgr)

{

int ret = OB_SUCCESS;

t_session_mgr = OB_NEW(ObTenantSQLSessionMgr, ObMemAttr(MTL_ID(), "TSQLSessionMgr"),

MTL_ID());

if (OB_ISNULL(t_session_mgr)) {

ret = OB_ALLOCATE_MEMORY_FAILED;

LOG_WARN("failed to alloc tenant session manager", K(ret));

} else if (OB_FAIL(t_session_mgr->init())) {

LOG_WARN("failed to init tenant session manager", K(ret));

}

return ret;

}

void ObTenantSQLSessionMgr::mtl_destroy(ObTenantSQLSessionMgr *&t_session_mgr)

{

if (nullptr != t_session_mgr) {

t_session_mgr->destroy();

OB_DELETE(ObTenantSQLSessionMgr, "unused", t_session_mgr);

t_session_mgr = nullptr;

}

}

ObSQLSessionInfo *ObTenantSQLSessionMgr::alloc_session()

{

int ret = OB_SUCCESS;

ObSQLSessionInfo *session = NULL;

OX (session_pool_.pop_session(session));

if (OB_ISNULL(session)) {

OX (session = op_instance_alloc_args(&session_allocator_,

ObSQLSessionInfo,

tenant_id_));

}

OV (OB_NOT_NULL(session));

OX (session->set_tenant_session_mgr(this));

OX (session->set_valid(true));

OX (session->set_shadow(true));

return session;

}

void ObTenantSQLSessionMgr::free_session(ObSQLSessionInfo *session)

{

int ret = OB_SUCCESS;

SessionPool *session_pool = NULL;

// add tracepoint for control session pool.

int64_t code = 0;

code = OB_E(EventTable::EN_SESS_POOL_MGR_CTRL) OB_SUCCESS;

if (ObTenantSQLSessionMgr::is_valid_tenant_id(session->get_login_tenant_id()) &&

session->can_release_to_pool() && code == OB_SUCCESS) {

if (session->is_use_inner_allocator() && !session->is_tenant_killed()) {

session_pool = &session_pool_;

}

}

if (OB_NOT_NULL(session_pool)) {

OX (session->destroy(true));

OX (session->set_acquire_from_pool(true));

OX (session_pool->push_session(session));

}

if (OB_NOT_NULL(session)) {

OX (op_free(session));

OX (session = NULL);

}

}

void ObTenantSQLSessionMgr::clean_session_pool()

{

int ret = OB_SUCCESS;

ObSQLSessionInfo *session = NULL;

// 注意，这里并没有从设计上保证session池一定被彻底清空，有极低概率会有少量遗留session：

// 1. 在生产系统中，删除租户是非常少见的操作。

// 2. 在生产系统中，删除租户前一定会先保证业务层不再访问该租户。

// 以上前提下，理论上该session池已经没有任何操作。

// 3. 正常停掉某个observer，但即使有少数session遗漏，也会随着进程结束而释放。

// 4. unit迁移等情况，可能会有少数session未被释放，但将来unit再迁回后可复用。

while (session_pool_.count() > 0) {

OX (session_pool_.pop_session(session));

if (OB_NOT_NULL(session)) {

OX (op_free(session));

OX (session = NULL);

}

}

}

bool ObTenantSQLSessionMgr::is_valid_tenant_id(uint64_t tenant_id) const

{

return ::is_valid_tenant_id(tenant_id) &&

tenant_id != OB_INVALID_ID &&

tenant_id != OB_SYS_TENANT_ID;

}

int ObSQLSessionMgr::ValueAlloc::clean_tenant(uint64_t tenant_id)

{

int ret = OB_SUCCESS;

MTL_SWITCH(tenant_id) {

auto *t_session_mgr = MTL(ObTenantSQLSessionMgr*);

t_session_mgr->clean_session_pool();

} else {

LOG_ERROR("switch tenant failed", K(ret), K(tenant_id));

}

return ret;

}

ObSQLSessionInfo *ObSQLSessionMgr::ValueAlloc::alloc_value(uint64_t tenant_id)

{

int ret = OB_SUCCESS;

ObSQLSessionInfo *session = NULL;

int64_t alloc_total_count = 0;

// we use OX instead of OZ in operation of upper session pool, because we need acquire

// from lower session pool when not success, no matter which errno we get here.

MTL_SWITCH(tenant_id) {

auto *t_session_mgr = MTL(ObTenantSQLSessionMgr*);

if (OB_ISNULL(session = t_session_mgr->alloc_session())) {

ret = OB_ALLOCATE_MEMORY_FAILED;

LOG_WARN("fail to alloc session", K(ret));

}

if (OB_SUCC(ret)) {

if (OB_FAIL(GCTX.session_mgr_->get_sess_hold_map()

.set_refactored(reinterpret_cast<uint64_t>(session), session))) {

LOG_WARN("fail to set session", K(ret), KP(session));

}

}

OX (alloc_total_count = ATOMIC_FAA(&alloc_total_count_, 1));

if (alloc_total_count > 0 && alloc_total_count % 10000 == 0) {

LOG_INFO("alloc_session_count", K(alloc_total_count));

}

} else {

LOG_ERROR("switch tenant failed", K(ret), K(tenant_id));

}

return session;

}

void ObSQLSessionMgr::ValueAlloc::free_value(ObSQLSessionInfo *session)

{

if (OB_NOT_NULL(session)) {

int ret = OB_SUCCESS;

uint64_t tenant_id = session->get_login_tenant_id();

int64_t free_total_count = 0;

// delete from hold map, ingore error

int tmp_ret = OB_SUCCESS;

if (OB_SUCCESS != (tmp_ret = GCTX.session_mgr_->get_sess_hold_map().erase_refactored(

reinterpret_cast<uint64_t>(session)))) {

LOG_WARN("fail to erase session", K(session->get_sessid()), K(tmp_ret), KP(session));

}

auto *t_session_mgr = session->get_tenant_session_mgr();

if (t_session_mgr != NULL) {

t_session_mgr->free_session(session);

}

OX (free_total_count = ATOMIC_FAA(&free_total_count_, 1));

if (free_total_count > 0 && free_total_count % 10000 == 0) {

LOG_INFO("free_session_count", K(free_total_count));

}

ObActiveSessionGuard::setup_default_ash();

}

}

int ObSQLSessionMgr::init()

{

int ret = OB_SUCCESS;

if (OB_FAIL(sessinfo_map_.init())) {

LOG_WARN("fail to init session map", K(ret));

} else if (OB_FAIL(sessid_sequence_.init(MAX_LOCAL_SEQ))) {

LOG_WARN("init sessid sequence failed", K(ret));

} else if (OB_FAIL(sess_hold_map_.create(BUCKET_COUNT,

SET_USE_500("SessHoldMapBuck"),

SET_USE_500("SessHoldMapNode")))) {

LOG_WARN("failed to init sess_hold_map", K(ret));

}

for (uint32_t i = 1; OB_SUCC(ret) && i <= MAX_LOCAL_SEQ; ++i) {

if (OB_FAIL(sessid_sequence_.push(reinterpret_cast<void*>(i)))) {

LOG_WARN("store sessid sequence failed", K(ret), K(i));

}

}

return ret;

}

void ObSQLSessionMgr::destroy()

{

sessinfo_map_.destroy();

sessid_sequence_.destroy();

sess_hold_map_.destroy();

}

uint64_t ObSQLSessionMgr::extract_server_id(uint32_t sessid)

{

uint64_t server_id = sessid >> LOCAL_SEQ_LEN;

return server_id & MAX_SERVER_ID;

}

int ObSQLSessionMgr::inc_session_ref(const ObSQLSessionInfo *my_session)

{

int ret = OB_SUCCESS;

if (OB_NOT_NULL(my_session)) {

ObSQLSessionInfo *tmp_session = NULL;

uint32_t sessid = my_session->get_sessid();

if (OB_FAIL(get_session(sessid, tmp_session))) {

LOG_WARN("fail to get session", K(sessid), K(ret));

}

UNUSED(tmp_session);

}

return ret;

}

// |<---------------------------------32bit---------------------------->|

// 0b 1b 15b 16b

// +----+------------------------------+--------------------------------+

// |Mask| Server Id | Local Seq |

// +----+------------------------------+--------------------------------+

//

//MASK: 1 表示是server自己生成connection id,

// 0 表示是proxy生成的connection id(已废弃，目前仅用于 in_mgr = false 的场景)；

//Server Id: 集群中server的id由RS分配，集群内唯一；

//Local Seq: 一个server可用连接数，目前单台server最多有INT16_MAX个连接;

//

int ObSQLSessionMgr::create_sessid(uint32_t &sessid, bool in_mgr)

{

int ret = OB_SUCCESS;

int tmp_ret = OB_SUCCESS;

sessid = 0;

const uint64_t server_id = GCTX.server_id_;

uint32_t local_seq = 0;

static uint32_t abnormal_seq = 0;//用于server_id == 0是的sessid分配

if (server_id > MAX_SERVER_ID) {

ret = OB_ERR_UNEXPECTED;

LOG_ERROR("server id maybe invalid", K(ret), K(server_id));

} else if (!in_mgr) {

sessid = (GETTID() | LOCAL_SESSID_TAG);

sessid |= static_cast<uint32_t>(server_id << LOCAL_SEQ_LEN); // set observer

} else if (0 == server_id) {

local_seq = (ATOMIC_FAA(&abnormal_seq, 1) & MAX_LOCAL_SEQ);

uint32_t max_local_seq = MAX_LOCAL_SEQ;

uint32_t max_server_id = MAX_SERVER_ID;

LOG_WARN("server is initiating", K(server_id), K(local_seq), K(max_local_seq), K(max_server_id));

} else if (OB_UNLIKELY(OB_SUCCESS != (ret = tmp_ret = get_avaiable_local_seq(local_seq)))) {

LOG_WARN("fail to get avaiable local_seq", K(local_seq));

} else {/*do nothing*/}

if (OB_SUCC(ret) && in_mgr) {

sessid = local_seq | SERVER_SESSID_TAG;// set observer sessid mark

sessid |= static_cast<uint32_t>(server_id << LOCAL_SEQ_LEN); // set observer

// high bit is reserved for server id

sessid |= static_cast<uint32_t>(1ULL << (LOCAL_SEQ_LEN + SERVER_ID_LEN));

}

return ret;

}

//ret == OB_SUCCESS时,保证sess_info != NULL, 需要在外面进行revert_session

//ret != OB_SUCCESS时，保证sess_info == NULL, 不需要在外面进行revert_session

int ObSQLSessionMgr::create_session(ObSMConnection *conn, ObSQLSessionInfo *&sess_info)

{

int ret = OB_SUCCESS;

sess_info = NULL;

if (OB_ISNULL(conn)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("conn is NULL", K(ret));

} else if (OB_FAIL(create_session(conn->tenant_id_,

conn->sessid_,

conn->proxy_sessid_,

conn->sess_create_time_,

sess_info))) {

LOG_WARN("create session failed", K(ret));

} else if (OB_ISNULL(sess_info)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("sess_info is null", K(ret));

} else {

sess_info->set_vid(conn->vid_);

sess_info->set_vip(conn->vip_buf_);

sess_info->set_vport(conn->vport_);

sess_info->inc_in_bytes(conn->connect_in_bytes_);

}

return ret;

}

int ObSQLSessionMgr::create_session(const uint64_t tenant_id,

const uint32_t sessid,

const uint64_t proxy_sessid,

const int64_t create_time,

ObSQLSessionInfo *&session_info)

{

int ret = OB_SUCCESS;

int err = OB_SUCCESS;

session_info = NULL;

ObSQLSessionInfo *tmp_sess = NULL;

if (OB_FAIL(sessinfo_map_.create(tenant_id, Key(sessid, proxy_sessid), tmp_sess))) {

LOG_WARN("fail to create session", K(ret), K(sessid));

if (OB_ENTRY_EXIST == ret) {

ret = OB_SESSION_ENTRY_EXIST;

}

} else if (OB_ISNULL(tmp_sess)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("fail to alloc session info", K(ret), K(sessid), K(proxy_sessid));

} else {

// create session contains a 'get_session' action implicitly

const bool v = GCONF._enable_trace_session_leak;

if (OB_UNLIKELY(v)) {

tmp_sess->on_get_session();

}

}

if (OB_FAIL(ret)) {

// pass

} else if (OB_FAIL(tmp_sess->init(sessid, proxy_sessid, NULL, NULL, create_time,

tenant_id))) {

LOG_WARN("fail to init session", K(ret), K(tmp_sess),

K(sessid), K(proxy_sessid), K(create_time));

if (FALSE_IT(revert_session(tmp_sess))) {

LOG_ERROR("fail to free session", K(err), K(sessid), K(proxy_sessid));

} else if (OB_SUCCESS != (err = sessinfo_map_.del(Key(sessid)))) {

LOG_ERROR("fail to free session", K(err), K(sessid), K(proxy_sessid));

} else {

LOG_DEBUG("free session successfully in create session", K(err),

K(sessid), K(proxy_sessid));

}

} else {

// set tenant info to session, if has.

ObFLTControlInfoManager mgr(tenant_id);

if (OB_FAIL(mgr.init())) {

LOG_WARN("failed to init full link control info", K(ret));

if (FALSE_IT(revert_session(tmp_sess))) {

LOG_ERROR("fail to free session", K(err), K(sessid), K(proxy_sessid));

} else if (OB_SUCCESS != (err = sessinfo_map_.del(Key(sessid)))) {

LOG_ERROR("fail to free session", K(err), K(sessid), K(proxy_sessid));

} else {

LOG_DEBUG("free session successfully in create session", K(err),

K(sessid), K(proxy_sessid));

}

} else if (mgr.is_valid_tenant_config()) {

tmp_sess->set_flt_control_info(mgr.get_control_info());

}

if (OB_FAIL(ret)) {

// do nothing

} else {

tmp_sess->update_last_active_time();

session_info = tmp_sess;

}

}

return ret;

}

int ObSQLSessionMgr::free_session(const ObFreeSessionCtx &ctx)

{

int ret = OB_SUCCESS;

uint32_t sessid = ctx.sessid_;

uint64_t proxy_sessid = ctx.proxy_sessid_;

uint64_t tenant_id = ctx.tenant_id_;

bool has_inc = ctx.has_inc_active_num_;

ObSQLSessionInfo *sess_info = NULL;

sessinfo_map_.get(Key(sessid), sess_info);

if (NULL != sess_info) {

#ifdef OB_BUILD_AUDIT_SECURITY

if (!sess_info->get_is_deserialized()) {

ObString empty_comment_text;

sess_info->update_alive_time_stat();

int64_t cur_timeout_backup = THIS_WORKER.get_timeout_ts();

THIS_WORKER.set_timeout_ts(ObTimeUtility::current_time() + OB_MAX_USER_SPECIFIED_TIMEOUT);

ObSecurityAuditUtils::handle_security_audit(*sess_info,

stmt::T_LOGOFF,

ObString::make_string("DISCONNECT"),

empty_comment_text,

ret);

THIS_WORKER.set_timeout_ts(cur_timeout_backup);

}

#endif

if (OB_UNLIKELY(OB_SUCCESS != sess_info->on_user_disconnect())) {

LOG_WARN("user disconnect failed", K(ret), K(sess_info->get_user_id()));

}

sessinfo_map_.revert(sess_info);

}

if (OB_FAIL(sessinfo_map_.del(Key(sessid)))) {

LOG_WARN("fail to remove session from session map", K(ret), K(sessid), K(proxy_sessid));

} else if (tenant_id != 0 && sessid != 0 && has_inc) {

ObTenantStatEstGuard guard(tenant_id);

EVENT_DEC(ACTIVE_SESSIONS);

}

return ret;

}

void ObSQLSessionMgr::try_check_session()

{

int ret = OB_SUCCESS;

CheckSessionFunctor check_timeout(this);

if (OB_FAIL(for_each_session(check_timeout))) {

LOG_WARN("fail to check time out", K(ret));

} else {

if (REACH_TIME_INTERVAL(60000000)) { // 60s

OZ (check_session_leak());

}

}

}

int ObSQLSessionMgr::get_min_active_snapshot_version(share::SCN &snapshot_version)

{

int ret = OB_SUCCESS;

concurrency_control::GetMinActiveSnapshotVersionFunctor min_active_txn_version_getter;

if (OB_FAIL(for_each_session(min_active_txn_version_getter))) {

LOG_WARN("fail to get min active snapshot version", K(ret));

} else {

snapshot_version = min_active_txn_version_getter.get_min_active_snapshot_version();

}

return ret;

}

int ObSQLSessionMgr::check_session_leak()

{

int ret = OB_SUCCESS;

int64_t hold_session_count = sess_hold_map_.size();

int64_t used_session_count = 0;

if (OB_FAIL(get_session_count(used_session_count))) {

LOG_WARN("fail to get session count", K(ret));

} else {

static const int32_t DEFAULT_SESSION_LEAK_COUNT_THRESHOLD = 100;

int64_t session_leak_count_threshold = - EVENT_CALL(EventTable::EN_SESSION_LEAK_COUNT_THRESHOLD);

session_leak_count_threshold = session_leak_count_threshold > 0

? session_leak_count_threshold

: DEFAULT_SESSION_LEAK_COUNT_THRESHOLD;

LOG_INFO("get current session count", K(used_session_count), K(hold_session_count),

K(session_leak_count_threshold));

if (hold_session_count - used_session_count >= session_leak_count_threshold) {

LOG_ERROR("session leak!!!", "leak_count", hold_session_count - used_session_count,

K(used_session_count), K(hold_session_count));

DumpHoldSession dump_session;

OZ(for_each_hold_session(dump_session));

}

}

return ret;

}

void ObSQLSessionMgr::runTimerTask()

{

try_check_session();

}

// just a wrapper

int ObSQLSessionMgr::kill_query(ObSQLSessionInfo &session)

{

return kill_query(session, ObSQLSessionState::QUERY_KILLED);

}

int ObSQLSessionMgr::set_query_deadlocked(ObSQLSessionInfo &session)

{

return kill_query(session, ObSQLSessionState::QUERY_DEADLOCKED);

}

int ObSQLSessionMgr::kill_query(ObSQLSessionInfo &session,

const ObSQLSessionState status)

{

int ret = OB_SUCCESS;

int tmp_ret = OB_SUCCESS;

//如果start_stmt/end_stmt卡住，此时需要先唤醒sql线程，然后再设置标记，否则kill session不起作用

if (OB_SUCCESS != (tmp_ret = ObSqlTransControl::kill_query_session(session, status))) {

LOG_WARN("fail to kill query or session", "ret", tmp_ret, K(session));

}

if (ObSQLSessionState::QUERY_KILLED == status) {

ret = session.kill_query();

} else if (ObSQLSessionState::QUERY_DEADLOCKED == status) {

ret = session.set_query_deadlocked();

} else {

LOG_WARN("unexpected status", K(status));

ret = OB_ERR_UNEXPECTED;

}

return ret;

}

// kill idle timeout transaction on this session

int ObSQLSessionMgr::kill_idle_timeout_tx(ObSQLSessionInfo *session)

{

return ObSqlTransControl::kill_idle_timeout_tx(session);

}

// kill deadlock transaction on this session

int ObSQLSessionMgr::kill_deadlock_tx(ObSQLSessionInfo *session)

{

return ObSqlTransControl::kill_deadlock_tx(session);

}

int ObSQLSessionMgr::kill_session(ObSQLSessionInfo &session)

{

int ret = OB_SUCCESS;

int tmp_ret = OB_SUCCESS;

//如果start_stmt/end_stmt卡住，此时需要先唤醒sql线程，然后再设置标记，否则kill session不起作用

if (OB_SUCCESS != (tmp_ret = ObSqlTransControl::kill_query_session(

session, ObSQLSessionState::SESSION_KILLED))) {

LOG_WARN("fail to kill query or session", "ret", tmp_ret, K(session));

}

session.set_session_state(SESSION_KILLED);

// NOTE: 下面两个guard的顺序不可更换，否则有机会形成死锁

ObSQLSessionInfo::LockGuard query_lock_guard(session.get_query_lock());

ObSQLSessionInfo::LockGuard data_lock_guard(session.get_thread_data_lock());

bool need_disconnect = false;

session.set_query_start_time(ObTimeUtility::current_time());

if (session.is_in_transaction()) {

auto tx_desc = session.get_tx_desc();

if (OB_SUCCESS != (tmp_ret = ObSqlTransControl::kill_tx_on_session_killed(&session))) {

LOG_WARN("fail to rollback transaction", K(session.get_sessid()),

"proxy_sessid", session.get_proxy_sessid(),

K(tmp_ret), KPC(tx_desc),

"query_str", session.get_current_query_string(),

K(need_disconnect));

}

}

session.update_last_active_time();

session.set_disconnect_state(NORMAL_KILL_SESSION);

rpc::ObSqlSockDesc &sock_desc = session.get_sock_desc();

if (OB_LIKELY(NULL != sock_desc.sock_desc_)) {

SQL_REQ_OP.disconnect_by_sql_sock_desc(sock_desc);

// this function will trigger on_close(), and then free the session

LOG_INFO("kill session successfully",

"proxy", session.get_proxy_addr(),

"peer", session.get_peer_addr(),

"real_client_ip", session.get_client_ip(),

"sessid", session.get_sessid(),

"proxy_sessid", session.get_proxy_sessid(),

"query_str", session.get_current_query_string());

} else {

LOG_WARN("get conn from session info is null", K(session.get_sessid()),

"proxy_sessid", session.get_proxy_sessid(), K(session.get_magic_num()));

}

return ret;

}

int ObSQLSessionMgr::disconnect_session(ObSQLSessionInfo &session)

{

int ret = OB_SUCCESS;

// NOTE: 下面两个guard的顺序不可更换，否则有机会形成死锁

ObSQLSessionInfo::LockGuard query_lock_guard(session.get_query_lock());

ObSQLSessionInfo::LockGuard data_lock_guard(session.get_thread_data_lock());

bool need_disconnect = false;

session.set_query_start_time(ObTimeUtility::current_time());

// 调用这个函数之前会在ObSMHandler::on_disconnect中调session.set_session_state(SESSION_KILLED)，

if (session.is_in_transaction()) {

auto tx_desc = session.get_tx_desc();

if (OB_FAIL(ObSqlTransControl::kill_tx_on_session_disconnect(&session))) {

LOG_WARN("fail to rollback transaction", K(session.get_sessid()),

"proxy_sessid", session.get_proxy_sessid(), K(ret),

KPC(tx_desc),

"query_str", session.get_current_query_string(),

K(need_disconnect));

}

}

session.update_last_active_time();

return ret;

}

int ObSQLSessionMgr::kill_tenant(const uint64_t tenant_id)

{

int ret = OB_SUCCESS;

KillTenant kt_func(this, tenant_id);

OZ (for_each_session(kt_func));

OZ (sessinfo_map_.clean_tenant(tenant_id));

return ret;

}

int ObSQLSessionMgr::mark_sessid_used(uint32_t sess_id)

{

//这个接口是为了以前老版本解决proxy sessid复用添加的

//现在的版本(从2.0开始)里不会再有switch_sessid的需求，因此这里不用再提供

UNUSED(sess_id);

return OB_NOT_SUPPORTED;

}

int ObSQLSessionMgr::mark_sessid_unused(uint32_t sess_id)

{

int ret = OB_SUCCESS;

uint64_t server_id = extract_server_id(sess_id);

if (server_id == 0) {

// 参考：create_sessid方法

// 由于server_id == 0时, 此时的local_seq，是由ATOMIC_FAA(&abnormal_seq, 1)产生，

// 使用ATOMIC_FAA的原因无从考证（原作者的信息描述无任何具体信息），采取保守修改策略

// local_seq未曾从sessid_sequence_队列中获取,所以不需要归还到队列，不然会导致队列溢出的bug

// bug详情:

} else if (OB_FAIL(sessid_sequence_.push(reinterpret_cast<void*>(sess_id & MAX_LOCAL_SEQ)))) {

LOG_WARN("fail to push sessid to sessid_sequence_", K(sess_id), K(ret));

}

return ret;

}

bool ObSQLSessionMgr::CheckSessionFunctor::operator()(sql::ObSQLSessionMgr::Key key,

ObSQLSessionInfo *sess_info)

{

int ret = OB_SUCCESS;

UNUSED(key);

bool is_timeout = false;

if (OB_ISNULL(sess_info)) {

ret = OB_NOT_INIT;

LOG_WARN("session info is NULL");

} else if (false == sess_info->is_valid()) {

ret = OB_INVALID_ARGUMENT;

LOG_WARN("session info is not valid", K(ret));

} else {

int callback_retcode = OB_SUCCESS;

transaction::ObITxCallback *commit_cb = NULL;

// NOTE: 下面两个guard的顺序不可更换，否则有机会形成死锁

if (OB_FAIL(sess_info->try_lock_query())) {

if (OB_UNLIKELY(OB_EAGAIN != ret)) {

LOG_WARN("fail to try lock query", K(ret));

} else {

ret = OB_SUCCESS;

}

} else {

if (OB_FAIL(sess_info->try_lock_thread_data())) {

if (OB_UNLIKELY(OB_EAGAIN != ret)) {

LOG_WARN("fail to try lock thread data", K(ret));

} else {

ret = OB_SUCCESS;

}

} else {

if (OB_ISNULL(sess_mgr_)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("session manager point is NULL");

} else if (OB_FAIL(sess_info->is_timeout(is_timeout))) {

LOG_WARN("fail to check is timeout", K(ret));

} else if (true == is_timeout) {

LOG_INFO("session is timeout, kill this session", K(key.sessid_));

ret = sess_mgr_->kill_session(*sess_info);

} else if (sess_info->is_txn_free_route_temp()) {

sess_info->check_txn_free_route_alive();

} else {

//借助于session遍历的功能，尝试revert session上缓存的schema guard，

//避免长时间持有guard，导致schema mgr的槽位无法释放

sess_info->get_cached_schema_guard_info().try_revert_schema_guard();

//定期更新租户级别的配置项，避免频繁获取租户级配置项给性能带来的开销

sess_info->refresh_tenant_config();

// send client commit result if txn commit timeout

if (OB_FAIL(sess_info->is_trx_commit_timeout(commit_cb, callback_retcode))) {

LOG_WARN("fail to check transaction commit timeout", K(ret));

} else if (commit_cb) {

LOG_INFO("transaction commit reach timeout", K(callback_retcode), K(key.sessid_));

} else if (OB_FAIL(sess_info->is_trx_idle_timeout(is_timeout))) {

// kill transaction which is idle more than configuration 'ob_trx_idle_timeout'

LOG_WARN("fail to check transaction idle timeout", K(ret));

} else if (true == is_timeout && !sess_info->associated_xa()) {

LOG_INFO("transaction is idle timeout, start to rollback", K(key.sessid_));

int tmp_ret;

if (OB_SUCCESS != (tmp_ret = sess_mgr_->kill_idle_timeout_tx(sess_info))) {

LOG_WARN("fail to kill transaction", K(ret), K(key.sessid_));

}

}

}

(void)sess_info->unlock_thread_data();

}

(void)sess_info->unlock_query();

// NOTE: must execute callback after release query_lock

if (commit_cb) {

commit_cb->callback(callback_retcode);

}

}

}

return OB_SUCCESS == ret;

}

bool ObSQLSessionMgr::KillTenant::operator() (

sql::ObSQLSessionMgr::Key, ObSQLSessionInfo *sess_info)

{

int ret = OB_SUCCESS;

if (OB_ISNULL(mgr_)) {

ret = OB_NOT_INIT;

LOG_WARN("session mgr_ is NULL", K(mgr_));

} else if (OB_ISNULL(sess_info)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("sess info is NULL", K(sess_info));

} else {

if (sess_info->get_priv_tenant_id() == tenant_id_ ||

sess_info->get_effective_tenant_id() == tenant_id_) {

ret = mgr_->kill_session(*sess_info);

}

}

return OB_SUCCESS == ret;

}

int ObSQLSessionMgr::get_avaiable_local_seq(uint32_t &local_seq)

{

int ret = OB_SUCCESS;

local_seq = 0;

void *ptr = nullptr;

if (OB_FAIL(sessid_sequence_.pop(ptr))) {

LOG_WARN("fail to find and set first zero bit", K(ret));

} else {

int64_t value = reinterpret_cast<int64_t>(ptr);

if (value > MAX_LOCAL_SEQ) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("unexpected value from bitset", K(ret), K(value), K(ptr));

} else {

local_seq = static_cast<uint32_t>(value);

}

}

if (OB_ENTRY_NOT_EXIST == ret) {

ret = OB_ERR_CON_COUNT_ERROR;

int64_t sess_count = 0;

(void)get_session_count(sess_count);

LOG_WARN("too many connection", "connection_count", sess_count, K(ret));

}

return ret;

}

int ObSQLSessionMgr::is_need_clear_sessid(const ObSMConnection *conn, bool &is_need)

{

int ret = OB_SUCCESS;

is_need = false;

if (OB_ISNULL(conn)) {

ret = OB_ERR_UNEXPECTED;

LOG_WARN("unexpected parameter", K(conn));

} else if (is_server_sessid(conn->sessid_)

&& ObSMConnection::INITIAL_SESSID != conn->sessid_

&& 0 != extract_server_id(conn->sessid_)

&& GCTX.server_id_ == extract_server_id(conn->sessid_)

&& conn->is_need_clear_sessid_) {

is_need = true;

} else {/*do nothing*/ }

return ret;

}

int ObSQLSessionMgr::DumpHoldSession::operator()(

common::hash::HashMapPair<uint64_t, ObSQLSessionInfo *> &entry)

{

int ret = common::OB_SUCCESS;

if (OB_ISNULL(entry.second)) {

LOG_INFO("session is null", "sess_ptr", entry.first);

} else {

LOG_INFO("dump session", "sid", entry.second->get_sessid(),

"ref_count", entry.second->get_sess_ref_cnt(),

"state",ObString::make_string(entry.second->get_session_state_str()),

KP(entry.second),

K(entry.first),

"lbt", entry.second->get_sess_bt());

}

return ret;

}

ObSessionGetterGuard::ObSessionGetterGuard(ObSQLSessionMgr &sess_mgr, uint32_t sessid)

: mgr_(sess_mgr), session_(NULL)

{

ret_ = mgr_.get_session(sessid, session_);

if (OB_SUCCESS != ret_) {

LOG_WARN_RET(ret_, "get session fail", K(ret_), K(sessid));

} else {

NG_TRACE_EXT(session, OB_ID(sid), session_->get_sessid(),

OB_ID(tenant_id), session_->get_priv_tenant_id());

}

}

ObSessionGetterGuard::~ObSessionGetterGuard()

{

if (session_) {

mgr_.revert_session(session_);

}

}