Hello, > Sometime ago, I wrote that when we send TERM to imapd (although it would > happen with any other I assume, pop, sieve...) procceses we wanted to exit,
When and where have you written this? I observe that sometimes stopping master, by sending it SIGTERM, triggers an endless loop there waiting for some child to terminate - https://cyrus.topicbox.com/groups/devel/Tea1dbf8f58b01177-Mec77eb0e4f3ec3641e7e0191/the-master-janitor-goes-crazy-re-debugging-deadlocks . This leads to 100% CPU utilization because of that loop. It happens repeatedly, but I do not know how to reproduce this. I thought https://github.com/cyrusimap/cyrus-imapd/pull/3449 is a fix, but it is not. Does your proposal approach the problem that on SIGTERM the master process enters endless loop? Greetings Дилян -----Original Message----- From: egoitz via Devel <devel@cyrus.topicbox.com> Reply-To: Devel <devel@cyrus.topicbox.com> To: devel@cyrus.topicbox.com Subject: Services in READY state and MAX_READY_FAILS in less than MAX_READY_FAIL_INTERVAL Date: 10/09/24 19:55:04 Hi!, Sometime ago, I wrote that when we send TERM to imapd (although it would happen with any other I assume, pop, sieve...) procceses we wanted to exit, due to a user request for disconnecting his/her sessions, sometimes happened that was like, after that sessions disconnection (TERM to imapd processes) no enough processes where become spawned newly. Only sometimes when very few processes needed to be killed. I have been able to reproduce it. If a user has connected (because proctitle() has set it in the name) and later in very few time "leaves" (logouts for instance) and then the process moves to READY state if you kill with TERM more than MAX_READY_FAILS units of that process in less than MAX_READY_FAIL_INTERVAL, master won't spawn new processes as it's written in master.c in lines near 1100 in reap_child() function. It's suggested to launch a SIGHUP to master for activating again the service, but it can't be enabled again because the service seems to have removed from the s data structure but not stopped. Due to that non process stop, when new imapd attemps to load (in service_create() ) it can't be created because the socket is still in use. So, for ensuring this is correct, I have written the following patch for master.c and that I tested on 3.0.15 : root@debugcyrus:/usr/ports/mail/cyrus-imapd30 # diff -u work/cyrus-imapd-3.0.15/master/master.c /master.c-definitivo --- work/cyrus-imapd-3.0.15/master/master.c 2021-03-09 04:27:45.000000000 +0100 +++ /master.c-definitivo 2024-09-10 18:36:49.797581000 +0200 @@ -129,6 +129,11 @@ }; static int verbose = 0; + +/* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ +static int gotsigurg = 0; +/* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ + static int listen_queue_backlog = 32; static int pidfd = -1; @@ -1047,6 +1052,22 @@ } } +/* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ +static void sigurg_handler(int sig __attribute__((unused))) +{ + syslog(LOG_DEBUG, "URG CAPTURADO!!!!!!"); + + if (gotsigurg) + { + gotsigurg = 0; + } + else + { + gotsigurg = 1; + } +} +/* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ + static void reap_child(void) { int status; @@ -1094,10 +1115,24 @@ "terminated abnormally", SERVICEPARAM(s->name), SERVICEPARAM(s->familyname), pid); - if (now - s->lastreadyfail > MAX_READY_FAIL_INTERVAL) { + + syslog(LOG_DEBUG, "Senal URG vale.... --%d--",gotsigurg); + + if ((now - s->lastreadyfail > MAX_READY_FAIL_INTERVAL) || (gotsigurg)) + { s->nreadyfails = 0; + + if (gotsigurg) + { + syslog(LOG_DEBUG, "RESETEANDO...."); + syslog(LOG_DEBUG, "RESETEADO...."); + } } + + syslog(LOG_DEBUG, "too many failures for service %s/%s, resetting counters due to SIGURG received in Cyrus master. El got vale --%d--",SERVICEPARAM(s->name),SERVICEPARAM(s->familyname),gotsigurg); + s->lastreadyfail = now; + if (++s->nreadyfails >= MAX_READY_FAILS && s->exec) { syslog(LOG_ERR, "too many failures for " "service %s/%s, disabling until next SIGHUP", @@ -1305,11 +1340,18 @@ sigemptyset(&action.sa_mask); action.sa_handler = sighup_handler; + #ifdef SA_RESTART action.sa_flags |= SA_RESTART; #endif if (sigaction(SIGHUP, &action, NULL) < 0) fatalf(1, "unable to install signal handler for SIGHUP: %m"); + + /* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ + action.sa_handler = sigurg_handler; + if (sigaction(SIGURG, &action, NULL) < 0) + fatalf(1, "unable to install signal handler for SIGURG: %m"); + /* RESET MAX_READY_FAILS OF SERVICE IN MASTER WRAPPER */ action.sa_handler = sigalrm_handler; if (sigaction(SIGALRM, &action, NULL) < 0) root@debugcyrus:/usr/ports/mail/cyrus-imapd30 # So by what I have seen Cyrus wrapper is written (and the way it handles services), I think that the possible solutions could be : * Send a kill(pid,SIGTERM) for ensuring the process die before forgetting from s structure. * Do something similar as I have done, which gives you a time window for having more failures than expected for some seconds and which later could be undone with for instance the same signal sending. Reproduced and something proposed at least. What do you think about it? :) Cheers! sarenet Egoitz Aurrekoetxea Departamento de sistemas 94 - 420 94 70 ego...@sarenet.es www.sarenet.es Parque Tecnológico. Edificio 103 48170 Zamudio (Bizkaia) servicios sarenet Antes de imprimir este correo electrónico piense si es necesario hacerlo. Cyrus / Devel / seediscussions +participants +delivery options Permalink ------------------------------------------ Cyrus: Devel Permalink: https://cyrus.topicbox.com/groups/devel/Tf9f7cf579fff1397-Mf19f7988d7f009e1c4b82bac Delivery options: https://cyrus.topicbox.com/groups/devel/subscription
