1)会以O_RDWR | O_CREAT | O_EXCL形式open,若存在的话会返回创建文件失败。
(postmaster.c:5989) ==37795== by 0x56626C: process_pm_child_exit (postmaster.c:3106) ==37795==...by 0x56626C: ServerLoop (postmaster.c:1771) ==37795== by 0x5687D5: PostmasterMain (postmaster.c:1466...(postmaster.c:5989) ==37799== by 0x56626C: process_pm_child_exit (postmaster.c:3106) ==37799==...by 0x56626C: ServerLoop (postmaster.c:1771) ==37799== by 0x5687D5: PostmasterMain (postmaster.c:1466...(postmaster.c:5989) ==37944== by 0x56626C: process_pm_child_exit (postmaster.c:3106) ==37944==
2、备机startup会等待recoveryWakeupLatch、POSTMASTER_FD_WATCH两个事件,两个事件其实都是管道的read端,然后用epoll_wait等待。...[POSTMASTER_FD_WATCH]、超时(请见2.1WaitLatchOrSocket) 2、唤醒后把锁信息全部清理掉,并把epoll_create创建的fd关掉close(set->epoll_fd...[POSTMASTER_FD_WATCH]的等待,记录为一个wakeEvents 4、wakeEvents汇总到WaitEventSet中 5、调用epoll_wait等上面两把锁 或 超时唤醒 6、清理...&& IsUnderPostmaster) AddWaitEventToSet(set, WL_POSTMASTER_DEATH, PGINVALID_SOCKET, NULL,...和上流程相同,不同的是event->fd = postmaster_alive_fds[POSTMASTER_FD_WATCH] *******************************
二、分析:该信息打印位置,从后面代码段do_start函数中可以看出 1、pg_ctl start调用start_postmaster启动PG的主进程后,每隔0.1ms检查一次postmaster.pid....将pmState=PM_RECOVERY 四、代码分析 1、pg_ctl start流程 do_start-> pm_pid = start_postmaster(); if (do_wait){...print_msg(_("waiting for server to start...")); switch (wait_for_postmaster(pm_pid, false)){ case...POSTMASTER_READY: print_msg(_(" done\n")); print_msg(_("server started\n")); break; case POSTMASTER_STILL_STARTING...\n"), progname); exit(1); break; } }else print_msg(_("server starting\n")); wait_for_postmaster-
二、分析:该信息打印位置,从后面代码段do_start函数中可以看出 1、pg_ctl start调用start_postmaster启动PG的主进程后,每隔0.1ms检查一次postmaster.pid....将pmState=PM_RECOVERY 四、代码分析 1、pg_ctl start流程 do_start-> pm_pid = start_postmaster(); if (do_wait...){ print_msg(_("waiting for server to start...")); switch (wait_for_postmaster(pm_pid..., false)){ case POSTMASTER_READY: print_msg(_(" done\n")); ...print_msg(_("server started\n")); break; case POSTMASTER_STILL_STARTING:
0x7ffe04557c20) at bootstrap.c:426 #4 0x00000000007e0710 in StartChildProcess (type=StartupProcess) at postmaster.c...:5463 #5 0x00000000007db5bb in PostmasterMain (argc=3, argv=0x1a79c80) at postmaster.c:1377 #6 0x00000000007195f6...0x7ffe04557c20) at bootstrap.c:426 #5 0x00000000007e0710 in StartChildProcess (type=StartupProcess) at postmaster.c...:5463 #6 0x00000000007db5bb in PostmasterMain (argc=3, argv=0x1a79c80) at postmaster.c:1377 #7 0x00000000007195f6...:5463 #4 0x00000000007ddadd in reaper (postgres_signal_arg=17) at postmaster.c:2936 #5 <signal handler
missing = 0 20230310:11:43:10:001214 gpstate:gpdb6:gpadmin-[INFO]:- Total number of postmaster.pid...found = 2 20230310:11:43:10:001214 gpstate:gpdb6:gpadmin-[INFO]:- Total number postmaster...missing = 0 20230310:11:43:10:001214 gpstate:gpdb6:gpadmin-[INFO]:- Total number postmaster...found = 2 20230310:11:43:10:001214 gpstate:gpdb6:gpadmin-[INFO]:- Total number postmaster...missing = 0 20230310:11:43:10:001214 gpstate:gpdb6:gpadmin-[INFO]:- Total number postmaster
减少大量用户统一时间访问的资源征用 wal buffer是临时存储数据库的变化,wal buffer的日志数据定期会flush到wal file PostgreSQL 进程模型 PostgreSQL进程类型 Postmaster...Daemon 进程(postmaster process) PostgreSQL Background进程(background process) PostgreSQL Backend进程(backend...process) 图片 Postmaster Daemon 进程 图片 Postmaster进程是PostgreSQL启动的第一个进程,它的主要工作是负责执行数据库的recovery、初始化shared
,nevens表示注册的事件个数,nevents_space表示该Set最多可以管理事件个数,比如WaitLatchOrSocket函数中这个变量值为3,仅可以管理事件WL_LATCH_SET、WL_POSTMASTER_DEATH...可以设置的事件包括以下几种: WL_LATCH_SET:等待latch被set WL_POSTMASTER_DEATH:等待postmaster die WL_SOCKET_READABLE:等待socket...可读 WL_SOCKET_WRITEABLE:等待socket可写 WL_EXIT_ON_PM_DEATH:postmaster死了后立即退出。...AddWaitEventToSet函数中可以看到若事件WL_EXIT_ON_PM_DEATH则立即改成WL_POSTMASTER_DEATH,也就是说在postmaster进程挂了后可以探测到,并退出。
Bianry,Avro,Parquest,ORC格式 2 Greenplum SQL的执行过程 0、The system at rest 1、Client connects via the entry postmaster...2、Entry postmaster forks a new backend -- the QD 3、QD connects to segment via the segment postmasters...return status to QD 10、QD returns result set and status to the client 2.1 系统空闲状态 1、1个master,2个segment 11、postmaster...进程会监听到链接请求,并处理 2.3 Master fork一个进程处理客户端请求 1、Master 上的postmaster 进程监听到链接请求后,fork一个子进程用于处理该客户端的所有查询请求...PostgrsSQL中称为backend;在Greenplum中该进程称为QD 2.4 QD建立和Segment的链接 1、QD进程使用libpq协议和每个segment建立链接请求 2、Segment上的postmaster
在POSTGRESQL 中各个backend processes 之间是无法看到相互的内存使用的情况, Postmaster 本身也不能查看backend process 内存....但各个进程之间要进行互访的情况下, postmaster 就必须要跟踪每个进程的情况....在POSTGRESQL 的守护进程Postmaster 接收到了客户的连接请求,会开始为客户启动一个backend 进程, src/backend/postmaster/postmaster.c 压力测试中发现连接在
postgres", username=0x8bb7f14 "pg") at postgres.c:4236 #15 0x083db09d in BackendRun (port=0x8bb49b8) at postmaster.c...:4431 #16 0x083da896 in BackendStartup (port=0x8bb49b8) at postmaster.c:4122 #17 0x083d6dff in ServerLoop...() at postmaster.c:1704 #18 0x083d674d in PostmasterMain (argc=1, argv=0x8b8d808) at postmaster.c:1377...:4431 #16 0x083da896 in BackendStartup (port=0x8bb49b8) at postmaster.c:4122 #17 0x083d6dff in ServerLoop...() at postmaster.c:1704 #18 0x083d674d in PostmasterMain (argc=1, argv=0x8b8d808) at postmaster.c:1377
pg_multixact pg_replslot pg_snapshots pg_stat_tmp pg_tblspc PG_VERSION postgresql.auto.conf postmaster.opts...删除一些就的身份信息,归档日志文件等 rm -rf data/pg_xlog/ mkdir -p data/pg_xlog/archive_status rm data/postmaster.pid 15...启动Hot-Standby: /usr/pgsql-9.4/bin/postmaster -D /var/lib/pgsql/9.4/data --port=5432 20....S 14:26 0:00 /usr/pgsql-9.4/bin/postmaster -D /var/lib/pgsql/9.4/data postgres...S 17:49 0:00 /usr/pgsql-9.4/bin/postmaster -D /var/lib/pgsql/9.4/data postgres 11510 0.0 0.0 324796
2.初始化AntDB-T动态共享内存(DSM)在 postmaster 主进程启动时,调用dsm_postmaster_startup(PGShmemHeader *shim)函数,进行动态共享内存相关的初始化...清理AntDB-T动态共享内存(DSM)在 postmaster 主进程关闭时,会调用 dsm_postmaster_shutdown() 函数进行 dsm 的清理,这个函数是在初始化动态共享内存(dsm_postmaster_startup...())时就指定了on_shmem_exit(dsm_postmaster_shutdown, PointerGetDatum(shim));清理动态共享内存的主要逻辑:首先检查动态共享内存段是否已经损坏...主进程在处理时,发现需要进行并行处理,就会在启动从进程时,会调用 LaunchParallelWorkers 函数,这个函数会调用RegisterDynamicBackgroundWorker ,此时会给 Postmaster...进程发一个信号,请求 Postmaster 进程启动一个 background 进程,Postmaster 进程收到信号后就会启动一个新后台进程来处理查询。
master) = 0 20230131:16:37:05:021525 gpstate:mdw1:gpadmin-[INFO]:- Total number of postmaster.pid...found = 16 20230131:16:37:05:021525 gpstate:mdw1:gpadmin-[INFO]:- Total number of postmaster.pid...found = 16 20230131:16:37:05:021525 gpstate:mdw1:gpadmin-[INFO]:- Total number postmaster...found = 16 20230131:16:37:05:021525 gpstate:mdw1:gpadmin-[INFO]:- Total number postmaster...| head -1` || echo -1 20230201:13:47:51:016069 gpactivatestandby:mdw2:gpadmin-[INFO]:-found standby postmaster
报错提示如下:致命:锁定文件“ postmaster.pid”已存在”原因:多数是因为安装了多个不同版本的Postgresql数据库后,导致安装的根目录下面有多个data文件夹,从而出现postmaster.pid
在 PostgreSQL 中,同样可以通过查询得到类似的效果: 1 select pg_postmaster_start_time()as START_SINCE, 2 date_part('day...',current_timestamp-pg_postmaster_start_time())||'day(s),'|| 3 date_part('hour',current_timestamp-pg_postmaster_start_time...())||'hour(s),'|| 4 date_part('minutes',current_timestamp-pg_postmaster_start_time())||'minute(s),'|...1 select date_trunc('day',current_timestamp-pg_postmaster_start_time()); 2 date_trunc 3 ---------...--- 4 26 days 5 (1 row) 6 eygle=# selectdate_trunc('hour',current_timestamp-pg_postmaster_start_time
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