/* -*-pgpool_logger-c-*- */ /* * $Header$ * * pgpool: a language independent connection pool server for PostgreSQL * written by Tatsuo Ishii * * Copyright (c) 2003-2023 PgPool Global Development Group * * Permission to use, copy, modify, and distribute this software and * its documentation for any purpose and without fee is hereby * granted, provided that the above copyright notice appear in all * copies and that both that copyright notice and this permission * notice appear in supporting documentation, and that the name of the * author not be used in advertising or publicity pertaining to * distribution of the software without specific, written prior * permission. The author makes no representations about the * suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. */ /*------------------------------------------------------------------------- * * From: PostgreSQL * src/backend/postmaster/syslogger.c * Copyright (c) 2004-2020, PostgreSQL Global Development Group *------------------------------------------------------------------------- */ #include #include #include #include #include #include #include #include #include #include #include "pool.h" #include "pool_config.h" #include "utils/palloc.h" #include "utils/memutils.h" #include "utils/elog.h" #include "parser/pg_list.h" #include "parser/stringinfo.h" #include "utils/ps_status.h" #include "utils/timestamp.h" #include "utils/pool_signal.h" #include "main/pgpool_logger.h" #define DEVNULL "/dev/null" typedef int64 pg_time_t; /* * We read() into a temp buffer twice as big as a chunk, so that any fragment * left after processing can be moved down to the front and we'll still have * room to read a full chunk. */ #define READ_BUF_SIZE (2 * PIPE_CHUNK_SIZE) /* Log rotation signal file path, relative to $PGDATA */ #define LOGROTATE_SIGNAL_FILE "logrotate" /* * GUC parameters. Logging_collector cannot be changed after postmaster * start, but the rest can change at SIGHUP. */ bool redirection_done = false; /* * Private state */ static pg_time_t next_rotation_time; static bool pipe_eof_seen = false; static bool rotation_disabled = false; static FILE *syslogFile = NULL; static FILE *csvlogFile = NULL; static pg_time_t first_syslogger_file_time = 0; static char *last_file_name = NULL; static char *last_csv_file_name = NULL; /* * Buffers for saving partial messages from different backends. * * Keep NBUFFER_LISTS lists of these, with the entry for a given source pid * being in the list numbered (pid % NBUFFER_LISTS), so as to cut down on * the number of entries we have to examine for any one incoming message. * There must never be more than one entry for the same source pid. * * An inactive buffer is not removed from its list, just held for re-use. * An inactive buffer has pid == 0 and undefined contents of data. */ typedef struct { int32 pid; /* PID of source process */ StringInfoData data; /* accumulated data, as a StringInfo */ } save_buffer; #define NBUFFER_LISTS 256 static List *buffer_lists[NBUFFER_LISTS]; int syslogPipe[2] = {-1, -1}; /* * Flags set by interrupt handlers for later service in the main loop. */ static volatile sig_atomic_t got_SIGHUP = false; static volatile sig_atomic_t rotation_requested = false; static void SysLoggerMain(int argc, char *argv[]) pg_attribute_noreturn(); static void process_pipe_input(char *logbuffer, int *bytes_in_logbuffer); static void flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer); static FILE *logfile_open(const char *filename, const char *mode, bool allow_errors); static void logfile_rotate(bool time_based_rotation, int size_rotation_for); static char *logfile_getname(pg_time_t timestamp, const char *suffix); static void set_next_rotation_time(void); static void sigHupHandler(int sig); static void sigUsr1Handler(int sig); /* * Main entry point for syslogger process * argc/argv parameters are valid only in EXEC_BACKEND case. */ static void SysLoggerMain(int argc, char *argv[]) { char logbuffer[READ_BUF_SIZE]; int bytes_in_logbuffer = 0; char *currentLogDir; char *currentLogFilename; int currentLogRotationAge; pg_time_t now; now = time(NULL); init_ps_display("", "", "", ""); set_ps_display("PgpoolLogger", false); /* * If we restarted, our stderr is already redirected into our own input * pipe. This is of course pretty useless, not to mention that it * interferes with detecting pipe EOF. Point stderr to /dev/null. This * assumes that all interesting messages generated in the syslogger will * come through elog.c and will be sent to write_syslogger_file. */ if (redirection_done) { int fd = open(DEVNULL, O_WRONLY, 0); /* * The closes might look redundant, but they are not: we want to be * darn sure the pipe gets closed even if the open failed. We can * survive running with stderr pointing nowhere, but we can't afford * to have extra pipe input descriptors hanging around. * * As we're just trying to reset these to go to DEVNULL, there's not * much point in checking for failure from the close/dup2 calls here, * if they fail then presumably the file descriptors are closed and * any writes will go into the bitbucket anyway. */ close(fileno(stdout)); close(fileno(stderr)); if (fd != -1) { (void) dup2(fd, fileno(stdout)); (void) dup2(fd, fileno(stderr)); close(fd); } } /* * Also close our copy of the write end of the pipe. This is needed to * ensure we can detect pipe EOF correctly. (But note that in the restart * case, the postmaster already did this.) */ if (syslogPipe[1] >= 0) close(syslogPipe[1]); syslogPipe[1] = -1; /* * Properly accept or ignore signals the postmaster might send us * * Note: we ignore all termination signals, and instead exit only when all * upstream processes are gone, to ensure we don't miss any dying gasps of * broken backends... */ pool_signal(SIGHUP, sigHupHandler); pool_signal(SIGINT, SIG_IGN); pool_signal(SIGTERM, SIG_IGN); pool_signal(SIGQUIT, SIG_IGN); pool_signal(SIGALRM, SIG_IGN); pool_signal(SIGPIPE, SIG_IGN); pool_signal(SIGUSR1, sigUsr1Handler); /* request log rotation */ pool_signal(SIGUSR2, SIG_IGN); /* * Reset some signals that are accepted by postmaster but not here */ pool_signal(SIGCHLD, SIG_DFL); POOL_SETMASK(&UnBlockSig); /* * Remember active logfiles' name(s). We recompute 'em from the reference * time because passing down just the pg_time_t is a lot cheaper than * passing a whole file path in the EXEC_BACKEND case. */ last_file_name = logfile_getname(first_syslogger_file_time, NULL); if (csvlogFile != NULL) last_csv_file_name = logfile_getname(first_syslogger_file_time, ".csv"); /* remember active logfile parameters */ currentLogDir = pstrdup(pool_config->log_directory); currentLogFilename = pstrdup(pool_config->log_filename); currentLogRotationAge = pool_config->log_rotation_age; /* set next planned rotation time */ set_next_rotation_time(); /* * Set up a reusable WaitEventSet object we'll use to wait for our latch, * and (except on Windows) our socket. * * Unlike all other postmaster child processes, we'll ignore postmaster * death because we want to collect final log output from all backends and * then exit last. We'll do that by running until we see EOF on the * syslog pipe, which implies that all other backends have exited * (including the postmaster). */ /* main worker loop */ for (;;) { bool time_based_rotation = false; int size_rotation_for = 0; struct timeval timeout; fd_set rfds; int rc; /* * Process any requests or signals received recently. */ if (got_SIGHUP) { got_SIGHUP = false; MemoryContext oldContext = MemoryContextSwitchTo(TopMemoryContext); pool_get_config(get_config_file_name(), CFGCXT_RELOAD); MemoryContextSwitchTo(oldContext); /* * Check if the log directory or filename pattern changed in * pgpool.conf. If so, force rotation to make sure we're * writing the logfiles in the right place. */ if (strcmp(pool_config->log_directory, currentLogDir) != 0) { pfree(currentLogDir); currentLogDir = pstrdup(pool_config->log_directory); rotation_requested = true; /* * Also, create new directory if not present; ignore errors */ if (mkdir(pool_config->log_directory, S_IREAD | S_IWRITE | S_IEXEC) == -1) { ereport(LOG, (errmsg("pgpool logger, failed to create directory:\"%s\". error:\"%m\"", pool_config->log_directory))); } } if (strcmp(pool_config->log_filename, currentLogFilename) != 0) { pfree(currentLogFilename); currentLogFilename = pstrdup(pool_config->log_filename); rotation_requested = true; } /* * Force a rotation if CSVLOG output was just turned on or off and * we need to open or close csvlogFile accordingly. */ if (((pool_config->log_destination & LOG_DESTINATION_CSVLOG) != 0) != (csvlogFile != NULL)) rotation_requested = true; /* * If rotation time parameter changed, reset next rotation time, * but don't immediately force a rotation. */ if (currentLogRotationAge != pool_config->log_rotation_age) { currentLogRotationAge = pool_config->log_rotation_age; set_next_rotation_time(); } /* * If we had a rotation-disabling failure, re-enable rotation * attempts after SIGHUP, and force one immediately. */ if (rotation_disabled) { rotation_disabled = false; rotation_requested = true; } } if (pool_config->log_rotation_age > 0 && !rotation_disabled) { /* Do a logfile rotation if it's time */ now = (pg_time_t) time(NULL); if (now >= next_rotation_time) rotation_requested = time_based_rotation = true; } if (!rotation_requested && pool_config->log_rotation_size > 0 && !rotation_disabled) { /* Do a rotation if file is too big */ if (ftell(syslogFile) >= pool_config->log_rotation_size * 1024L) { rotation_requested = true; size_rotation_for |= LOG_DESTINATION_STDERR; } if (csvlogFile != NULL && ftell(csvlogFile) >= pool_config->log_rotation_size * 1024L) { rotation_requested = true; size_rotation_for |= LOG_DESTINATION_CSVLOG; } } if (rotation_requested) { /* * Force rotation when both values are zero. It means the request * was sent by pcp_log_rotate. */ if (!time_based_rotation && size_rotation_for == 0) size_rotation_for = LOG_DESTINATION_STDERR | LOG_DESTINATION_CSVLOG; logfile_rotate(time_based_rotation, size_rotation_for); } /* * Calculate time till next time-based rotation, so that we don't * sleep longer than that. We assume the value of "now" obtained * above is still close enough. Note we can't make this calculation * until after calling logfile_rotate(), since it will advance * next_rotation_time. * * Also note that we need to beware of overflow in calculation of the * timeout: with large settings of pool_config->log_rotation_age, next_rotation_time * could be more than INT_MAX msec in the future. In that case we'll * wait no more than INT_MAX msec, and try again. */ timeout.tv_sec = 0; /* Reset usec everytime before calling sellect */ timeout.tv_usec = 0; if (pool_config->log_rotation_age > 0 && !rotation_disabled) { pg_time_t delay; delay = next_rotation_time - now; if (delay > 0) { if (delay > INT_MAX / 1000) delay = INT_MAX / 1000; timeout.tv_sec = delay; } } /* * Sleep until there's something to do */ FD_ZERO(&rfds); FD_SET(syslogPipe[0], &rfds); rc = select(syslogPipe[0] + 1, &rfds, NULL, NULL, timeout.tv_sec?&timeout:NULL); if (rc == 1) { int bytesRead; bytesRead = read(syslogPipe[0], logbuffer + bytes_in_logbuffer, sizeof(logbuffer) - bytes_in_logbuffer); if (bytesRead < 0) { if (errno != EINTR) ereport(LOG, (errmsg("could not read from logger pipe: %m"))); } else if (bytesRead > 0) { bytes_in_logbuffer += bytesRead; process_pipe_input(logbuffer, &bytes_in_logbuffer); continue; } else { /* * Zero bytes read when select() is saying read-ready means * EOF on the pipe: that is, there are no longer any processes * with the pipe write end open. Therefore, the postmaster * and all backends are shut down, and we are done. */ pipe_eof_seen = true; /* if there's any data left then force it out now */ flush_pipe_input(logbuffer, &bytes_in_logbuffer); } } if (pipe_eof_seen) { /* * seeing this message on the real stderr is annoying - so we make * it DEBUG1 to suppress in normal use. */ ereport(DEBUG1, (errmsg("logger shutting down"))); /* * Normal exit from the syslogger is here. Note that we * deliberately do not close syslogFile before exiting; this is to * allow for the possibility of elog messages being generated * inside proc_exit. Regular exit() will take care of flushing * and closing stdio channels. */ proc_exit(0); } } } /* * Postmaster subroutine to start a syslogger subprocess. */ int SysLogger_Start(void) { pid_t sysloggerPid; char *filename; if (!pool_config->logging_collector) return 0; /* * If first time through, create the pipe which will receive stderr * output. * * If the syslogger crashes and needs to be restarted, we continue to use * the same pipe (indeed must do so, since extant backends will be writing * into that pipe). * * This means the postmaster must continue to hold the read end of the * pipe open, so we can pass it down to the reincarnated syslogger. This * is a bit klugy but we have little choice. * * Also note that we don't bother counting the pipe FDs by calling * Reserve/ReleaseExternalFD. There's no real need to account for them * accurately in the postmaster or syslogger process, and both ends of the * pipe will wind up closed in all other postmaster children. */ if (syslogPipe[0] < 0) { if (pipe(syslogPipe) < 0) ereport(FATAL, (errmsg("could not create pipe for syslog: %m"))); } /* * Create log directory if not present; ignore errors */ mkdir(pool_config->log_directory, S_IREAD | S_IWRITE | S_IEXEC); /* * The initial logfile is created right in the postmaster, to verify that * the pool_config->log_directory is writable. We save the reference time so that the * syslogger child process can recompute this file name. * * It might look a bit strange to re-do this during a syslogger restart, * but we must do so since the postmaster closed syslogFile after the * previous fork (and remembering that old file wouldn't be right anyway). * Note we always append here, we won't overwrite any existing file. This * is consistent with the normal rules, because by definition this is not * a time-based rotation. */ first_syslogger_file_time = time(NULL); filename = logfile_getname(first_syslogger_file_time, NULL); syslogFile = logfile_open(filename, "a", false); pfree(filename); /* * Likewise for the initial CSV log file, if that's enabled. (Note that * we open syslogFile even when only CSV output is nominally enabled, * since some code paths will write to syslogFile anyway.) */ if (pool_config->log_destination & LOG_DESTINATION_CSVLOG) { filename = logfile_getname(first_syslogger_file_time, ".csv"); csvlogFile = logfile_open(filename, "a", false); pfree(filename); } switch ((sysloggerPid = fork())) { case -1: ereport(LOG, (errmsg("could not fork system logger: %m"))); return 0; case 0: on_exit_reset(); SetProcessGlobalVariables(PT_LOGGER); /* do the work */ SysLoggerMain(0, NULL); break; default: /* success, in postmaster */ /* now we redirect stderr, if not done already */ if (!redirection_done) { /* * Leave a breadcrumb trail when redirecting, in case the user * forgets that redirection is active and looks only at the * original stderr target file. */ ereport(LOG, (errmsg("redirecting log output to logging collector process"), errhint("Future log output will appear in directory \"%s\".", pool_config->log_directory))); #ifndef WIN32 fflush(stdout); if (dup2(syslogPipe[1], fileno(stdout)) < 0) ereport(FATAL, (errmsg("could not redirect stdout: %m"))); fflush(stderr); if (dup2(syslogPipe[1], fileno(stderr)) < 0) ereport(FATAL, (errmsg("could not redirect stderr: %m"))); /* Now we are done with the write end of the pipe. */ close(syslogPipe[1]); syslogPipe[1] = -1; #else /* * open the pipe in binary mode and make sure stderr is binary * after it's been dup'ed into, to avoid disturbing the pipe * chunking protocol. */ fflush(stderr); fd = _open_osfhandle((intptr_t) syslogPipe[1], _O_APPEND | _O_BINARY); if (dup2(fd, _fileno(stderr)) < 0) ereport(FATAL, (errmsg("could not redirect stderr: %m"))); close(fd); _setmode(_fileno(stderr), _O_BINARY); /* * Now we are done with the write end of the pipe. * CloseHandle() must not be called because the preceding * close() closes the underlying handle. */ syslogPipe[1] = 0; #endif redirection_done = true; } /* postmaster will never write the file(s); close 'em */ fclose(syslogFile); syslogFile = NULL; if (csvlogFile != NULL) { fclose(csvlogFile); csvlogFile = NULL; } return (int) sysloggerPid; } /* we should never reach here */ return 0; } /* -------------------------------- * pipe protocol handling * -------------------------------- */ /* * Process data received through the syslogger pipe. * * This routine interprets the log pipe protocol which sends log messages as * (hopefully atomic) chunks - such chunks are detected and reassembled here. * * The protocol has a header that starts with two nul bytes, then has a 16 bit * length, the pid of the sending process, and a flag to indicate if it is * the last chunk in a message. Incomplete chunks are saved until we read some * more, and non-final chunks are accumulated until we get the final chunk. * * All of this is to avoid 2 problems: * . partial messages being written to logfiles (messes rotation), and * . messages from different backends being interleaved (messages garbled). * * Any non-protocol messages are written out directly. These should only come * from non-Pgpool sources, however (e.g. third party libraries writing to * stderr). * * logbuffer is the data input buffer, and *bytes_in_logbuffer is the number * of bytes present. On exit, any not-yet-eaten data is left-justified in * logbuffer, and *bytes_in_logbuffer is updated. */ static void process_pipe_input(char *logbuffer, int *bytes_in_logbuffer) { char *cursor = logbuffer; int count = *bytes_in_logbuffer; int dest = LOG_DESTINATION_STDERR; /* While we have enough for a header, process data... */ while (count >= (int) (offsetof(PipeProtoHeader, data) + 1)) { PipeProtoHeader p; int chunklen; /* Do we have a valid header? */ memcpy(&p, cursor, offsetof(PipeProtoHeader, data)); if (p.nuls[0] == '\0' && p.nuls[1] == '\0' && p.len > 0 && p.len <= PIPE_MAX_PAYLOAD && p.pid != 0 && (p.is_last == 't' || p.is_last == 'f' || p.is_last == 'T' || p.is_last == 'F')) { List *buffer_list; ListCell *cell; save_buffer *existing_slot = NULL, *free_slot = NULL; StringInfo str; chunklen = PIPE_HEADER_SIZE + p.len; /* Fall out of loop if we don't have the whole chunk yet */ if (count < chunklen) break; dest = (p.is_last == 'T' || p.is_last == 'F') ? LOG_DESTINATION_CSVLOG : LOG_DESTINATION_STDERR; /* Locate any existing buffer for this source pid */ buffer_list = buffer_lists[p.pid % NBUFFER_LISTS]; foreach(cell, buffer_list) { save_buffer *buf = (save_buffer *) lfirst(cell); if (buf->pid == p.pid) { existing_slot = buf; break; } if (buf->pid == 0 && free_slot == NULL) free_slot = buf; } if (p.is_last == 'f' || p.is_last == 'F') { /* * Save a complete non-final chunk in a per-pid buffer */ if (existing_slot != NULL) { /* Add chunk to data from preceding chunks */ str = &(existing_slot->data); appendBinaryStringInfo(str, cursor + PIPE_HEADER_SIZE, p.len); } else { /* First chunk of message, save in a new buffer */ if (free_slot == NULL) { /* * Need a free slot, but there isn't one in the list, * so create a new one and extend the list with it. */ free_slot = palloc(sizeof(save_buffer)); buffer_list = lappend(buffer_list, free_slot); buffer_lists[p.pid % NBUFFER_LISTS] = buffer_list; } free_slot->pid = p.pid; str = &(free_slot->data); initStringInfo(str); appendBinaryStringInfo(str, cursor + PIPE_HEADER_SIZE, p.len); } } else { /* * Final chunk --- add it to anything saved for that pid, and * either way write the whole thing out. */ if (existing_slot != NULL) { str = &(existing_slot->data); appendBinaryStringInfo(str, cursor + PIPE_HEADER_SIZE, p.len); write_syslogger_file(str->data, str->len, dest); /* Mark the buffer unused, and reclaim string storage */ existing_slot->pid = 0; pfree(str->data); } else { /* The whole message was one chunk, evidently. */ write_syslogger_file(cursor + PIPE_HEADER_SIZE, p.len, dest); } } /* Finished processing this chunk */ cursor += chunklen; count -= chunklen; } else { /* Process non-protocol data */ /* * Look for the start of a protocol header. If found, dump data * up to there and repeat the loop. Otherwise, dump it all and * fall out of the loop. (Note: we want to dump it all if at all * possible, so as to avoid dividing non-protocol messages across * logfiles. We expect that in many scenarios, a non-protocol * message will arrive all in one read(), and we want to respect * the read() boundary if possible.) */ for (chunklen = 1; chunklen < count; chunklen++) { if (cursor[chunklen] == '\0') break; } /* fall back on the stderr log as the destination */ write_syslogger_file(cursor, chunklen, LOG_DESTINATION_STDERR); cursor += chunklen; count -= chunklen; } } /* We don't have a full chunk, so left-align what remains in the buffer */ if (count > 0 && cursor != logbuffer) memmove(logbuffer, cursor, count); *bytes_in_logbuffer = count; } /* * Force out any buffered data * * This is currently used only at syslogger shutdown, but could perhaps be * useful at other times, so it is careful to leave things in a clean state. */ static void flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer) { int i; /* Dump any incomplete protocol messages */ for (i = 0; i < NBUFFER_LISTS; i++) { List *list = buffer_lists[i]; ListCell *cell; foreach(cell, list) { save_buffer *buf = (save_buffer *) lfirst(cell); if (buf->pid != 0) { StringInfo str = &(buf->data); write_syslogger_file(str->data, str->len, LOG_DESTINATION_STDERR); /* Mark the buffer unused, and reclaim string storage */ buf->pid = 0; pfree(str->data); } } } /* * Force out any remaining pipe data as-is; we don't bother trying to * remove any protocol headers that may exist in it. */ if (*bytes_in_logbuffer > 0) write_syslogger_file(logbuffer, *bytes_in_logbuffer, LOG_DESTINATION_STDERR); *bytes_in_logbuffer = 0; } /* -------------------------------- * logfile routines * -------------------------------- */ /* * Write text to the currently open logfile * * This is exported so that elog.c can call it when processType is PT_LOGGER; . * This allows the syslogger process to record elog messages of its own, * even though its stderr does not point at the syslog pipe. */ void write_syslogger_file(const char *buffer, int count, int destination) { int rc; FILE *logfile; /* * If we're told to write to csvlogFile, but it's not open, dump the data * to syslogFile (which is always open) instead. This can happen if CSV * output is enabled after postmaster start and we've been unable to open * csvlogFile. There are also race conditions during a parameter change * whereby backends might send us CSV output before we open csvlogFile or * after we close it. Writing CSV-formatted output to the regular log * file isn't great, but it beats dropping log output on the floor. * * Think not to improve this by trying to open csvlogFile on-the-fly. Any * failure in that would lead to recursion. */ logfile = (destination == LOG_DESTINATION_CSVLOG && csvlogFile != NULL) ? csvlogFile : syslogFile; rc = fwrite(buffer, 1, count, logfile); /* * Try to report any failure. We mustn't use ereport because it would * just recurse right back here, but write_stderr is OK: it will write * either to the postmaster's original stderr, or to /dev/null, but never * to our input pipe which would result in a different sort of looping. */ if (rc != count) write_stderr("could not write to log file: %s\n", strerror(errno)); } /* * Open a new logfile with proper permissions and buffering options. * * If allow_errors is true, we just log any open failure and return NULL * (with errno still correct for the fopen failure). * Otherwise, errors are treated as fatal. */ static FILE * logfile_open(const char *filename, const char *mode, bool allow_errors) { FILE *fh; mode_t oumask; /* * Note we do not let pool_config->log_file_mode disable IWUSR, since we certainly want * to be able to write the files ourselves. */ oumask = umask((mode_t) ((~(pool_config->log_file_mode | S_IWUSR)) & (S_IRWXU | S_IRWXG | S_IRWXO))); fh = fopen(filename, mode); umask(oumask); if (fh) { setvbuf(fh, NULL, _IOLBF, 0); #ifdef WIN32 /* use CRLF line endings on Windows */ _setmode(_fileno(fh), _O_TEXT); #endif } else { int save_errno = errno; ereport(allow_errors ? LOG : FATAL, (errmsg("could not open log file \"%s\": %m", filename))); errno = save_errno; } return fh; } /* * perform logfile rotation */ static void logfile_rotate(bool time_based_rotation, int size_rotation_for) { char *filename; char *csvfilename = NULL; pg_time_t fntime; FILE *fh; rotation_requested = false; /* * When doing a time-based rotation, invent the new logfile name based on * the planned rotation time, not current time, to avoid "slippage" in the * file name when we don't do the rotation immediately. */ if (time_based_rotation) fntime = next_rotation_time; else fntime = time(NULL); filename = logfile_getname(fntime, NULL); if (pool_config->log_destination & LOG_DESTINATION_CSVLOG) csvfilename = logfile_getname(fntime, ".csv"); /* * Decide whether to overwrite or append. We can overwrite if (a) * pool_config->log_truncate_on_rotation is set, (b) the rotation was triggered by * elapsed time and not something else, and (c) the computed file name is * different from what we were previously logging into. * * Note: last_file_name should never be NULL here, but if it is, append. */ if (time_based_rotation || (size_rotation_for & LOG_DESTINATION_STDERR)) { if (pool_config->log_truncate_on_rotation && time_based_rotation && last_file_name != NULL && strcmp(filename, last_file_name) != 0) fh = logfile_open(filename, "w", true); else fh = logfile_open(filename, "a", true); if (!fh) { /* * ENFILE/EMFILE are not too surprising on a busy system; just * keep using the old file till we manage to get a new one. * Otherwise, assume something's wrong with pool_config->log_directory and stop * trying to create files. */ if (errno != ENFILE && errno != EMFILE) { ereport(LOG, (errmsg("disabling automatic rotation (use SIGHUP to re-enable)"))); rotation_disabled = true; } if (filename) pfree(filename); if (csvfilename) pfree(csvfilename); return; } fclose(syslogFile); syslogFile = fh; /* instead of pfree'ing filename, remember it for next time */ if (last_file_name != NULL) pfree(last_file_name); last_file_name = filename; filename = NULL; } /* * Same as above, but for csv file. Note that if LOG_DESTINATION_CSVLOG * was just turned on, we might have to open csvlogFile here though it was * not open before. In such a case we'll append not overwrite (since * last_csv_file_name will be NULL); that is consistent with the normal * rules since it's not a time-based rotation. */ if ((pool_config->log_destination & LOG_DESTINATION_CSVLOG) && (csvlogFile == NULL || time_based_rotation || (size_rotation_for & LOG_DESTINATION_CSVLOG))) { if (pool_config->log_truncate_on_rotation && time_based_rotation && last_csv_file_name != NULL && strcmp(csvfilename, last_csv_file_name) != 0) fh = logfile_open(csvfilename, "w", true); else fh = logfile_open(csvfilename, "a", true); if (!fh) { /* * ENFILE/EMFILE are not too surprising on a busy system; just * keep using the old file till we manage to get a new one. * Otherwise, assume something's wrong with pool_config->log_directory and stop * trying to create files. */ if (errno != ENFILE && errno != EMFILE) { ereport(LOG, (errmsg("disabling automatic rotation (use SIGHUP to re-enable)"))); rotation_disabled = true; } if (filename) pfree(filename); if (csvfilename) pfree(csvfilename); return; } if (csvlogFile != NULL) fclose(csvlogFile); csvlogFile = fh; /* instead of pfree'ing filename, remember it for next time */ if (last_csv_file_name != NULL) pfree(last_csv_file_name); last_csv_file_name = csvfilename; csvfilename = NULL; } else if (!(pool_config->log_destination & LOG_DESTINATION_CSVLOG) && csvlogFile != NULL) { /* CSVLOG was just turned off, so close the old file */ fclose(csvlogFile); csvlogFile = NULL; if (last_csv_file_name != NULL) pfree(last_csv_file_name); last_csv_file_name = NULL; } if (filename) pfree(filename); if (csvfilename) pfree(csvfilename); set_next_rotation_time(); } /* * construct logfile name using timestamp information * * If suffix isn't NULL, append it to the name, replacing any ".log" * that may be in the pattern. * * Result is palloc'd. */ static char * logfile_getname(pg_time_t timestamp, const char *suffix) { char *filename; int len; filename = palloc(MAXPGPATH); snprintf(filename, MAXPGPATH, "%s/", pool_config->log_directory); len = strlen(filename); /* treat pool_config->log_filename as a strftime pattern */ strftime(filename + len, MAXPGPATH - len, pool_config->log_filename, localtime(×tamp)); if (suffix != NULL) { len = strlen(filename); if (len > 4 && (strcmp(filename + (len - 4), ".log") == 0)) len -= 4; strlcpy(filename + len, suffix, MAXPGPATH - len); } return filename; } /* * Determine the next planned rotation time, and store in next_rotation_time. */ static void set_next_rotation_time(void) { pg_time_t now; struct tm *tm; int rotinterval; /* nothing to do if time-based rotation is disabled */ if (pool_config->log_rotation_age <= 0) return; /* * The requirements here are to choose the next time > now that is a * "multiple" of the log rotation interval. "Multiple" can be interpreted * fairly loosely. In this version we align to log_timezone rather than * GMT. */ rotinterval = pool_config->log_rotation_age * SECS_PER_MINUTE; /* convert to seconds */ now = (pg_time_t) time(NULL); tm = localtime(&now); now += tm->tm_gmtoff; now -= now % rotinterval; now += rotinterval; now -= tm->tm_gmtoff; next_rotation_time = now; } /* -------------------------------- * signal handler routines * -------------------------------- */ /* * Check to see if a log rotation request has arrived. Should be * called by postmaster after receiving SIGUSR1. */ bool CheckLogrotateSignal(void) { struct stat stat_buf; if (stat(LOGROTATE_SIGNAL_FILE, &stat_buf) == 0) return true; return false; } /* * Remove the file signaling a log rotation request. */ void RemoveLogrotateSignalFiles(void) { unlink(LOGROTATE_SIGNAL_FILE); } /* SIGHUP: set flag to reload config file */ static void sigHupHandler(int sig) { int save_errno = errno; got_SIGHUP = true; errno = save_errno; } /* SIGUSR1: set flag to rotate logfile */ static void sigUsr1Handler(int sig) { int save_errno = errno; rotation_requested = true; errno = save_errno; }