pg_upgrade.c

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/*
 *  pg_upgrade.c
 *
 *  main source file
 *
 *  Copyright (c) 2010-2013, PostgreSQL Global Development Group
 *  contrib/pg_upgrade/pg_upgrade.c
 */

/*
 *  To simplify the upgrade process, we force certain system values to be
 *  identical between old and new clusters:
 *
 *  We control all assignments of pg_class.oid (and relfilenode) so toast
 *  oids are the same between old and new clusters.  This is important
 *  because toast oids are stored as toast pointers in user tables.
 *
 *  FYI, while pg_class.oid and pg_class.relfilenode are initially the same
 *  in a cluster, but they can diverge due to CLUSTER, REINDEX, or VACUUM
 *  FULL.  The new cluster will have matching pg_class.oid and
 *  pg_class.relfilenode values and be based on the old oid value.  This can
 *  cause the old and new pg_class.relfilenode values to differ.  In summary,
 *  old and new pg_class.oid and new pg_class.relfilenode will have the
 *  same value, and old pg_class.relfilenode might differ.
 *
 *  We control all assignments of pg_type.oid because these oids are stored
 *  in user composite type values.
 *
 *  We control all assignments of pg_enum.oid because these oids are stored
 *  in user tables as enum values.
 *
 *  We control all assignments of pg_authid.oid because these oids are stored
 *  in pg_largeobject_metadata.
 */



#include "postgres_fe.h"

#include "pg_upgrade.h"

#ifdef HAVE_LANGINFO_H
#include <langinfo.h>
#endif

static void prepare_new_cluster(void);
static void prepare_new_databases(void);
static void create_new_objects(void);
static void copy_clog_xlog_xid(void);
static void set_frozenxids(void);
static void setup(char *argv0, bool *live_check);
static void cleanup(void);

ClusterInfo old_cluster,
            new_cluster;
OSInfo      os_info;

char       *output_files[] = {
    SERVER_LOG_FILE,
#ifdef WIN32
    /* unique file for pg_ctl start */
    SERVER_START_LOG_FILE,
#endif
    UTILITY_LOG_FILE,
    INTERNAL_LOG_FILE,
    NULL
};


int
main(int argc, char **argv)
{
    char       *sequence_script_file_name = NULL;
    char       *analyze_script_file_name = NULL;
    char       *deletion_script_file_name = NULL;
    bool        live_check = false;

    parseCommandLine(argc, argv);

    adjust_data_dir(&old_cluster);
    adjust_data_dir(&new_cluster);

    setup(argv[0], &live_check);

    output_check_banner(live_check);

    check_cluster_versions();

    get_sock_dir(&old_cluster, live_check);
    get_sock_dir(&new_cluster, false);

    check_cluster_compatibility(live_check);

    check_and_dump_old_cluster(live_check, &sequence_script_file_name);


    /* -- NEW -- */
    start_postmaster(&new_cluster, true);

    check_new_cluster();
    report_clusters_compatible();

    pg_log(PG_REPORT, "\nPerforming Upgrade\n");
    pg_log(PG_REPORT, "------------------\n");

    prepare_new_cluster();

    stop_postmaster(false);

    /*
     * Destructive Changes to New Cluster
     */

    copy_clog_xlog_xid();

    /* New now using xids of the old system */

    /* -- NEW -- */
    start_postmaster(&new_cluster, true);

    prepare_new_databases();

    create_new_objects();

    stop_postmaster(false);

    /*
     * Most failures happen in create_new_objects(), which has completed at
     * this point.  We do this here because it is just before linking, which
     * will link the old and new cluster data files, preventing the old
     * cluster from being safely started once the new cluster is started.
     */
    if (user_opts.transfer_mode == TRANSFER_MODE_LINK)
        disable_old_cluster();

    transfer_all_new_tablespaces(&old_cluster.dbarr, &new_cluster.dbarr,
                         old_cluster.pgdata, new_cluster.pgdata);

    /*
     * Assuming OIDs are only used in system tables, there is no need to
     * restore the OID counter because we have not transferred any OIDs from
     * the old system, but we do it anyway just in case.  We do it late here
     * because there is no need to have the schema load use new oids.
     */
    prep_status("Setting next OID for new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/pg_resetxlog\" -o %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_nxtoid,
              new_cluster.pgdata);
    check_ok();

    prep_status("Sync data directory to disk");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
              new_cluster.pgdata);
    check_ok();

    create_script_for_cluster_analyze(&analyze_script_file_name);
    create_script_for_old_cluster_deletion(&deletion_script_file_name);

    issue_warnings(sequence_script_file_name);

    pg_log(PG_REPORT, "\nUpgrade Complete\n");
    pg_log(PG_REPORT, "----------------\n");

    output_completion_banner(analyze_script_file_name,
                             deletion_script_file_name);

    pg_free(analyze_script_file_name);
    pg_free(deletion_script_file_name);
    pg_free(sequence_script_file_name);

    cleanup();

    return 0;
}


static void
setup(char *argv0, bool *live_check)
{
    char        exec_path[MAXPGPATH];   /* full path to my executable */

    /*
     * make sure the user has a clean environment, otherwise, we may confuse
     * libpq when we connect to one (or both) of the servers.
     */
    check_pghost_envvar();

    verify_directories();

    /* no postmasters should be running, except for a live check */
    if (pid_lock_file_exists(old_cluster.pgdata))
    {
        /*
         *  If we have a postmaster.pid file, try to start the server.  If
         *  it starts, the pid file was stale, so stop the server.  If it
         *  doesn't start, assume the server is running.  If the pid file
         *  is left over from a server crash, this also allows any committed
         *  transactions stored in the WAL to be replayed so they are not
         *  lost, because WAL files are not transfered from old to new
         *  servers.
         */     
        if (start_postmaster(&old_cluster, false))
            stop_postmaster(false);
        else
        {
            if (!user_opts.check)
                pg_log(PG_FATAL, "There seems to be a postmaster servicing the old cluster.\n"
                       "Please shutdown that postmaster and try again.\n");
            else
                *live_check = true;
        }
    }

    /* same goes for the new postmaster */
    if (pid_lock_file_exists(new_cluster.pgdata))
    {
        if (start_postmaster(&new_cluster, false))
            stop_postmaster(false);
        else
            pg_log(PG_FATAL, "There seems to be a postmaster servicing the new cluster.\n"
               "Please shutdown that postmaster and try again.\n");
    }

    /* get path to pg_upgrade executable */
    if (find_my_exec(argv0, exec_path) < 0)
        pg_log(PG_FATAL, "Could not get path name to pg_upgrade: %s\n", getErrorText(errno));

    /* Trim off program name and keep just path */
    *last_dir_separator(exec_path) = '\0';
    canonicalize_path(exec_path);
    os_info.exec_path = pg_strdup(exec_path);
}


static void
prepare_new_cluster(void)
{
    /*
     * It would make more sense to freeze after loading the schema, but that
     * would cause us to lose the frozenids restored by the load. We use
     * --analyze so autovacuum doesn't update statistics later
     */
    prep_status("Analyzing all rows in the new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/vacuumdb\" %s --all --analyze %s",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              log_opts.verbose ? "--verbose" : "");
    check_ok();

    /*
     * We do freeze after analyze so pg_statistic is also frozen. template0 is
     * not frozen here, but data rows were frozen by initdb, and we set its
     * datfrozenxid and relfrozenxids later to match the new xid counter
     * later.
     */
    prep_status("Freezing all rows on the new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/vacuumdb\" %s --all --freeze %s",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              log_opts.verbose ? "--verbose" : "");
    check_ok();

    get_pg_database_relfilenode(&new_cluster);
}


static void
prepare_new_databases(void)
{
    /*
     * We set autovacuum_freeze_max_age to its maximum value so autovacuum
     * does not launch here and delete clog files, before the frozen xids are
     * set.
     */

    set_frozenxids();

    prep_status("Restoring global objects in the new cluster");

    /*
     * Install support functions in the global-object restore database to
     * preserve pg_authid.oid.  pg_dumpall uses 'template0' as its template
     * database so objects we add into 'template1' are not propogated.  They
     * are removed on pg_upgrade exit.
     */
    install_support_functions_in_new_db("template1");

    /*
     * We have to create the databases first so we can install support
     * functions in all the other databases.  Ideally we could create the
     * support functions in template1 but pg_dumpall creates database using
     * the template0 template.
     */
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/psql\" " EXEC_PSQL_ARGS " %s -f \"%s\"",
              new_cluster.bindir, cluster_conn_opts(&new_cluster),
              GLOBALS_DUMP_FILE);
    check_ok();

    /* we load this to get a current list of databases */
    get_db_and_rel_infos(&new_cluster);
}


static void
create_new_objects(void)
{
    int         dbnum;

    prep_status("Adding support functions to new cluster");

    /*
     *  Technically, we only need to install these support functions in new
     *  databases that also exist in the old cluster, but for completeness
     *  we process all new databases.
     */
    for (dbnum = 0; dbnum < new_cluster.dbarr.ndbs; dbnum++)
    {
        DbInfo     *new_db = &new_cluster.dbarr.dbs[dbnum];

        /* skip db we already installed */
        if (strcmp(new_db->db_name, "template1") != 0)
            install_support_functions_in_new_db(new_db->db_name);
    }
    check_ok();

    prep_status("Restoring database schemas in the new cluster\n");

    for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
    {
        char sql_file_name[MAXPGPATH], log_file_name[MAXPGPATH];
        DbInfo     *old_db = &old_cluster.dbarr.dbs[dbnum];

        pg_log(PG_STATUS, "%s", old_db->db_name);
        snprintf(sql_file_name, sizeof(sql_file_name), DB_DUMP_FILE_MASK, old_db->db_oid);
        snprintf(log_file_name, sizeof(log_file_name), DB_DUMP_LOG_FILE_MASK, old_db->db_oid);

        /*
         *  pg_dump only produces its output at the end, so there is little
         *  parallelism if using the pipe.
         */
        parallel_exec_prog(log_file_name, NULL,
                  "\"%s/pg_restore\" %s --exit-on-error --verbose --dbname \"%s\" \"%s\"",
                  new_cluster.bindir, cluster_conn_opts(&new_cluster),
                  old_db->db_name, sql_file_name);
    }

    /* reap all children */
    while (reap_child(true) == true)
        ;

    end_progress_output();
    check_ok();

    /* regenerate now that we have objects in the databases */
    get_db_and_rel_infos(&new_cluster);

    uninstall_support_functions_from_new_cluster();
}

/*
 * Delete the given subdirectory contents from the new cluster, and copy the
 * files from the old cluster into it.
 */
static void
copy_subdir_files(char *subdir)
{
    char        old_path[MAXPGPATH];
    char        new_path[MAXPGPATH];

    prep_status("Deleting files from new %s", subdir);

    snprintf(old_path, sizeof(old_path), "%s/%s", old_cluster.pgdata, subdir);
    snprintf(new_path, sizeof(new_path), "%s/%s", new_cluster.pgdata, subdir);
    if (!rmtree(new_path, true))
        pg_log(PG_FATAL, "could not delete directory \"%s\"\n", new_path);
    check_ok();

    prep_status("Copying old %s to new server", subdir);

    exec_prog(UTILITY_LOG_FILE, NULL, true,
#ifndef WIN32
              "cp -Rf \"%s\" \"%s\"",
#else
    /* flags: everything, no confirm, quiet, overwrite read-only */
              "xcopy /e /y /q /r \"%s\" \"%s\\\"",
#endif
              old_path, new_path);

    check_ok();
}

static void
copy_clog_xlog_xid(void)
{
    /* copy old commit logs to new data dir */
    copy_subdir_files("pg_clog");

    /* set the next transaction id of the new cluster */
    prep_status("Setting next transaction ID for new cluster");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/pg_resetxlog\" -f -x %u \"%s\"",
              new_cluster.bindir, old_cluster.controldata.chkpnt_nxtxid,
              new_cluster.pgdata);
    check_ok();

    /*
     * If the old server is before the MULTIXACT_FORMATCHANGE_CAT_VER change
     * (see pg_upgrade.h) and the new server is after, then we don't copy
     * pg_multixact files, but we need to reset pg_control so that the new
     * server doesn't attempt to read multis older than the cutoff value.
     */
    if (old_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER &&
        new_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER)
    {
        copy_subdir_files("pg_multixact/offsets");
        copy_subdir_files("pg_multixact/members");
        prep_status("Setting next multixact ID and offset for new cluster");
        /*
         * we preserve all files and contents, so we must preserve both "next"
         * counters here and the oldest multi present on system.
         */
        exec_prog(UTILITY_LOG_FILE, NULL, true,
                  "\"%s/pg_resetxlog\" -O %u -m %u,%u \"%s\"",
                  new_cluster.bindir,
                  old_cluster.controldata.chkpnt_nxtmxoff,
                  old_cluster.controldata.chkpnt_nxtmulti,
                  old_cluster.controldata.chkpnt_oldstMulti,
                  new_cluster.pgdata);
        check_ok();
    }
    else if (new_cluster.controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER)
    {
        prep_status("Setting oldest multixact ID on new cluster");
        /*
         * We don't preserve files in this case, but it's important that the
         * oldest multi is set to the latest value used by the old system, so
         * that multixact.c returns the empty set for multis that might be
         * present on disk.  We set next multi to the value following that; it
         * might end up wrapped around (i.e. 0) if the old cluster had
         * next=MaxMultiXactId, but multixact.c can cope with that just fine.
         */
        exec_prog(UTILITY_LOG_FILE, NULL, true,
                  "\"%s/pg_resetxlog\" -m %u,%u \"%s\"",
                  new_cluster.bindir,
                  old_cluster.controldata.chkpnt_nxtmulti + 1,
                  old_cluster.controldata.chkpnt_nxtmulti,
                  new_cluster.pgdata);
        check_ok();
    }

    /* now reset the wal archives in the new cluster */
    prep_status("Resetting WAL archives");
    exec_prog(UTILITY_LOG_FILE, NULL, true,
              "\"%s/pg_resetxlog\" -l %s \"%s\"", new_cluster.bindir,
              old_cluster.controldata.nextxlogfile,
              new_cluster.pgdata);
    check_ok();
}


/*
 *  set_frozenxids()
 *
 *  We have frozen all xids, so set relfrozenxid and datfrozenxid
 *  to be the old cluster's xid counter, which we just set in the new
 *  cluster.  User-table frozenxid values will be set by pg_dumpall
 *  --binary-upgrade, but objects not set by the pg_dump must have
 *  proper frozen counters.
 */
static
void
set_frozenxids(void)
{
    int         dbnum;
    PGconn     *conn,
               *conn_template1;
    PGresult   *dbres;
    int         ntups;
    int         i_datname;
    int         i_datallowconn;

    prep_status("Setting frozenxid counters in new cluster");

    conn_template1 = connectToServer(&new_cluster, "template1");

    /* set pg_database.datfrozenxid */
    PQclear(executeQueryOrDie(conn_template1,
                              "UPDATE pg_catalog.pg_database "
                              "SET  datfrozenxid = '%u'",
                              old_cluster.controldata.chkpnt_nxtxid));

    /* get database names */
    dbres = executeQueryOrDie(conn_template1,
                              "SELECT   datname, datallowconn "
                              "FROM pg_catalog.pg_database");

    i_datname = PQfnumber(dbres, "datname");
    i_datallowconn = PQfnumber(dbres, "datallowconn");

    ntups = PQntuples(dbres);
    for (dbnum = 0; dbnum < ntups; dbnum++)
    {
        char       *datname = PQgetvalue(dbres, dbnum, i_datname);
        char       *datallowconn = PQgetvalue(dbres, dbnum, i_datallowconn);

        /*
         * We must update databases where datallowconn = false, e.g.
         * template0, because autovacuum increments their datfrozenxids and
         * relfrozenxids even if autovacuum is turned off, and even though all
         * the data rows are already frozen  To enable this, we temporarily
         * change datallowconn.
         */
        if (strcmp(datallowconn, "f") == 0)
            PQclear(executeQueryOrDie(conn_template1,
                                      "UPDATE pg_catalog.pg_database "
                                      "SET  datallowconn = true "
                                      "WHERE datname = '%s'", datname));

        conn = connectToServer(&new_cluster, datname);

        /* set pg_class.relfrozenxid */
        PQclear(executeQueryOrDie(conn,
                                  "UPDATE   pg_catalog.pg_class "
                                  "SET  relfrozenxid = '%u' "
        /* only heap, materialized view, and TOAST are vacuumed */
                                  "WHERE    relkind IN ('r', 'm', 't')",
                                  old_cluster.controldata.chkpnt_nxtxid));
        PQfinish(conn);

        /* Reset datallowconn flag */
        if (strcmp(datallowconn, "f") == 0)
            PQclear(executeQueryOrDie(conn_template1,
                                      "UPDATE pg_catalog.pg_database "
                                      "SET  datallowconn = false "
                                      "WHERE datname = '%s'", datname));
    }

    PQclear(dbres);

    PQfinish(conn_template1);

    check_ok();
}


static void
cleanup(void)
{

    fclose(log_opts.internal);

    /* Remove dump and log files? */
    if (!log_opts.retain)
    {
        int         dbnum;
        char      **filename;

        for (filename = output_files; *filename != NULL; filename++)
            unlink(*filename);

        /* remove dump files */
        unlink(GLOBALS_DUMP_FILE);

        if (old_cluster.dbarr.dbs)
            for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
            {
                char sql_file_name[MAXPGPATH], log_file_name[MAXPGPATH];
                DbInfo     *old_db = &old_cluster.dbarr.dbs[dbnum];

                snprintf(sql_file_name, sizeof(sql_file_name), DB_DUMP_FILE_MASK, old_db->db_oid);
                unlink(sql_file_name);

                snprintf(log_file_name, sizeof(log_file_name), DB_DUMP_LOG_FILE_MASK, old_db->db_oid);
                unlink(log_file_name);
            }
    }
}