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Diffstat (limited to 'grot.c')
| -rw-r--r-- | grot.c | 414 |
1 files changed, 414 insertions, 0 deletions
@@ -0,0 +1,414 @@ +/* This file is part of Grot. + Copyright (C) 2009 Sergey Poznyakoff + + Grot is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + Grot is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with grot. If not, see <http://www.gnu.org/licenses/>. */ + +#include "grot.h" +#include <sys/types.h> +#include <pwd.h> + +char *progname; + +#define DEBUG_QUERY(host, query) \ + do \ + if (verbose > 1) \ + printf("%s: query: %s\n", \ + host, query); \ + while (0) + +void +verror(MYSQL *mysql, char *fmt, va_list ap) +{ + fprintf(stderr, "%s: ", progname); + vfprintf(stderr, fmt, ap); + if (mysql) + fprintf(stderr, ": %s", mysql_error(mysql)); + fprintf(stderr, "\n"); +} + +void +terror(int code, MYSQL *mysql, char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + verror(mysql, fmt, ap); + va_end(ap); + if (code) + exit(code); +} + +void * +xmalloc(size_t size) +{ + void *p = malloc(size); + if (!p) + terror(1, NULL, "not enough memory"); + return p; +} + +void * +xzalloc(size_t size) +{ + void *p = xmalloc(size); + memset(p, 0, size); + return p; +} + +char * +xstrdup(char *str) +{ + char *p; + + if (!str) + return NULL; + p = xmalloc(strlen(str) + 1); + return strcpy(p, str); +} + +MYSQL mysql; + +struct config_file { + char *file; + char *group; +}; +struct config_file slave_files[] = { + { DEFAULT_USER_CONFIG, NULL }, /* group will be replaced by + the host name */ + { DEFAULT_USER_CONFIG, "slave" }, + { DEFAULT_SYSTEM_CONFIG, NULL }, /* likewise */ + { DEFAULT_SYSTEM_CONFIG, "slave" }, +}; +struct config_file master_files[] = { + { DEFAULT_USER_CONFIG, "grot" }, + { DEFAULT_SYSTEM_CONFIG, "grot" }, + { NULL, "grot" }, +}; + +#define NITEMS(a) sizeof(a)/sizeof((a)[0]) + +MYSQL * +try_connect(MYSQL *mp, struct config_file *cfg, int ncfg, + char *host, char *user, char *pass, + unsigned port, char *socket) +{ + int i; + MYSQL *ret; + + for (i = 0; i < ncfg; i++, cfg++) { + mysql_init(mp); + if (cfg->file) + mysql_options(mp, MYSQL_READ_DEFAULT_FILE, cfg->file); + if (cfg->group) + mysql_options(mp, MYSQL_READ_DEFAULT_GROUP, + cfg->group); + ret = mysql_real_connect(mp, host, user, pass, NULL, port, + socket, 0); + if (ret) + break; + mysql_close(mp); + } + return ret; +} + + +static void +do_connect() +{ + if (!try_connect(&mysql, master_files, NITEMS(master_files), + grot_host, + grot_user, + grot_password, + grot_port, + grot_socket)) + terror(1, &mysql, "cannot connect to master SQL server"); +} + +struct slave { + struct slave *next; + char *host; + + char *logfile; +}; + +unsigned long slave_count; +struct slave *slave_head, *slave_tail; + +void +add_slave(char *name, size_t len) +{ + struct slave *sp = xzalloc(sizeof(*sp)); + sp->host = xmalloc(len+1); + memcpy(sp->host, name, len); + sp->next = NULL; + sp->host[len] = 0; + if (slave_tail) + slave_tail->next = sp; + else + slave_head = sp; + slave_tail = sp; + slave_count++; +} + +/* + 0 1 2 3 4 + 401230 bind ns1.farlep.net:60446 (null) Binlog Dump 3837405 Has sent all binlog + to slave; waiting for binlog to be updated (null) +*/ +void +collect_slaves() +{ + MYSQL_RES *res; + size_t nrows, ncols, i; + + DEBUG_QUERY("master", "SHOW PROCESS LIST"); + res = mysql_list_processes(&mysql); + if (!res) + terror(1, &mysql, "cannot list processes"); + nrows = mysql_num_rows (res); + ncols = mysql_num_fields (res); + for (i = 0; i < nrows; i++) { + MYSQL_ROW row; + + mysql_data_seek (res, i); + row = mysql_fetch_row (res); + if (strcmp(row[4], "Binlog Dump") == 0) { + size_t len = strcspn(row[2], ":"); + add_slave(row[2], len); + } + } + mysql_free_result (res); +} + +void +list_slaves() +{ + unsigned long i; + struct slave *sp; + printf("No. of slaves: %lu\n", slave_count); + printf("Slave servers:\n"); + for (sp = slave_head, i = 0; sp; sp = sp->next, i++) + printf("%4ld: %s\n", i, sp->host); +} + +void +process_slave(struct slave *sp) +{ + MYSQL sm; + MYSQL_RES *res; + MYSQL_ROW row; + + if (verbose) + printf("Processing host %s\n", sp->host); + slave_files[0].group = slave_files[2].group = sp->host; + if (!try_connect(&sm, slave_files, NITEMS(slave_files), + sp->host, NULL, NULL, 0, NULL)) + terror(1, &sm, "cannot connect to slave server"); + + DEBUG_QUERY(sp->host, "SHOW SLAVE STATUS"); + + if (mysql_query(&sm, "SHOW SLAVE STATUS")) + terror(1, &sm, "%s: cannot get slave status", + sp->host); + res = mysql_store_result(&sm); + if (mysql_num_rows(res) < 1) + terror(1, NULL, "%s: empty slave status", + sp->host); + row = mysql_fetch_row (res); + if (verbose) + printf("%s: %s\n", sp->host, row[5]); + sp->logfile = xstrdup(row[5]); + mysql_free_result(res); + + mysql_close(&sm); +} + +void +collect_slave_logs() +{ + struct slave *sp; + + for (sp = slave_head; sp; sp = sp->next) + process_slave(sp); +} + +static char *log_prefix; +static size_t log_prefix_len; +static char *earliest_log; + +static char **server_log_table; +static size_t server_log_count; + +int +comp_log(const void *a, const void *b) +{ + return strcmp(*(char**)a, *(char**)b); +} + +char ** +find_server_log(char *log) +{ + return bsearch(&log, server_log_table, server_log_count, + sizeof(server_log_table[0]), comp_log); +} + +void +set_log_prefix() +{ + MYSQL_RES *res; + MYSQL_ROW row; + char *p; + size_t count, i; + + DEBUG_QUERY("master", "SHOW BINARY LOGS"); + if (mysql_query(&mysql, "SHOW BINARY LOGS")) + terror(1, &mysql, "cannot list binary logs on master"); + res = mysql_store_result(&mysql); + if (!res) + terror(1, &mysql, "cannot get result"); + count = mysql_num_rows(res); + row = mysql_fetch_row(res); + + p = strchr(row[0], '.'); + if (!p) + terror(1, NULL, + "unexpected binary log name: %s", row[0]); + log_prefix_len = p - row[0] + 1; + log_prefix = xmalloc(log_prefix_len + 1); + memcpy(log_prefix, row[0], log_prefix_len); + log_prefix[log_prefix_len] = 0; + if (verbose) + printf("Log prefix: %s\n", log_prefix); + + server_log_table = xmalloc(count*sizeof(server_log_table[0])); + server_log_count = count; + for (i = 0; i < count; i++) { + server_log_table[i] = xstrdup(row[0]); + row = mysql_fetch_row(res); + } + + qsort(server_log_table, server_log_count, sizeof(server_log_table[0]), + comp_log); + mysql_free_result(res); +} + + + +static int +logcmp(char *a, char *b) +{ + unsigned long na, nb; + + na = strtoul(a + log_prefix_len, NULL, 10); + nb = strtoul(b + log_prefix_len, NULL, 10); + if (na < nb) + return -1; + else if (na > nb) + return 1; + return 0; +} + +void +find_earliest_log() +{ + struct slave *sp; + + for (sp = slave_head; sp; sp = sp->next) { + if (strlen(sp->logfile) < log_prefix_len + || memcmp(sp->logfile, log_prefix, log_prefix_len)) { + terror(0, NULL, + "%s: logfile does not match base prefix: %s", + sp->host, sp->logfile); + continue; + } + if (!find_server_log(sp->logfile)) { + terror(0, NULL, + "Log %s is used by %s, but is absent on master", + sp->logfile, sp->host); + continue; + } + if (!earliest_log + || logcmp(sp->logfile, earliest_log) < 0) + earliest_log = sp->logfile; + } +} + +#define PURGE_TO_COMMAND "PURGE MASTER LOGS TO " + +void +purge_logs_to(char *logfile) +{ + char *buf = xmalloc(sizeof(PURGE_TO_COMMAND) + 2 + strlen(logfile)); + strcpy(buf, PURGE_TO_COMMAND); + strcat(buf, "'"); + strcat(buf, logfile); + strcat(buf, "'"); + DEBUG_QUERY("master", buf); + if (!dry_run_option && mysql_query(&mysql, buf)) + terror(1, &mysql, "failed to purge logs"); + free(buf); +} + +void +flush_logs() +{ + DEBUG_QUERY("master", "FLUSH LOGS"); + + if (!dry_run_option && mysql_query(&mysql, "FLUSH LOGS")) + terror(1, &mysql, "failed to purge logs"); +} + +int +main(int argc, char **argv) +{ + progname = argv[0]; + read_options(argc, argv); + + do_connect(); + set_log_prefix(); + collect_slaves(); + if (!slave_head) + terror(1, NULL, "No slaves"); + if (verbose) + list_slaves(); + collect_slave_logs(); + find_earliest_log(); + if (earliest_log) { + if (verbose) + printf("earliest common log: %s\n", earliest_log); + if (keep_count) { + char **p = find_server_log(earliest_log); + if (!p) + abort(); /* should not happen */ + p -= keep_count; + if (p < server_log_table) + earliest_log = NULL; + else + earliest_log = p[0]; + } + } + + if (earliest_log) { + purge_logs_to(earliest_log); + if (flush_logs_option) + flush_logs(); + } else { + if (verbose) + printf("Nothing to do\n"); + } + + mysql_close(&mysql); + exit(0); +} + |