logicalworker.h File Reference

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Functions
void	ApplyWorkerMain (Datum main_arg)
bool	IsLogicalWorker (void)

Function Documentation

ApplyWorkerMain()

void ApplyWorkerMain

(

Datum

main_arg

)

Definition at line 1565 of file worker.c.

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, am_tablesync_worker(), BackgroundWorkerInitializeConnectionByOid(), BackgroundWorkerUnblockSignals(), CacheRegisterSyscacheCallback(), CommitTransactionCommand(), Subscription::conninfo, DatumGetInt32, LogicalRepWorker::dbid, DEBUG1, die, elog, Subscription::enabled, ereport, errmsg(), ERROR, get_rel_name(), GetCurrentTimestamp(), GetSubscription(), invalidate_syncing_table_states(), LogicalRepWorker::last_recv_time, LogicalRepWorker::last_send_time, load_file(), LOG, WalRcvStreamOptions::logical, LOGICALREP_PROTO_VERSION_NUM, logicalrep_worker_attach(), logicalrep_worker_sighup(), LogicalRepApplyLoop(), LogicalRepSyncTableStart(), MemoryContextSwitchTo(), MyLogicalRepWorker, MySubscriptionValid, Subscription::name, NAMEDATALEN, Subscription::oid, OidIsValid, options, pfree(), PGC_BACKEND, PGC_S_OVERRIDE, PGC_SUSET, pqsignal(), proc_exit(), WalRcvStreamOptions::proto, pstrdup(), Subscription::publications, LogicalRepWorker::relid, replorigin_by_name(), replorigin_create(), replorigin_session_get_progress(), replorigin_session_origin, replorigin_session_setup(), LogicalRepWorker::reply_time, SetConfigOption(), SIGHUP, Subscription::slotname, WalRcvStreamOptions::slotname, snprintf, WalRcvStreamOptions::startpoint, StartTransactionCommand(), LogicalRepWorker::subid, subscription_change_cb(), SUBSCRIPTIONOID, SUBSCRIPTIONRELMAP, Subscription::synccommit, TopMemoryContext, LogicalRepWorker::userid, walrcv_connect, walrcv_identify_system, and walrcv_startstreaming.

{
    int         worker_slot = DatumGetInt32(main_arg);
    MemoryContext oldctx;
    char        originname[NAMEDATALEN];
    XLogRecPtr  origin_startpos;
    char       *myslotname;
    WalRcvStreamOptions options;

    /* Attach to slot */
    logicalrep_worker_attach(worker_slot);

    /* Setup signal handling */
    pqsignal(SIGHUP, logicalrep_worker_sighup);
    pqsignal(SIGTERM, die);
    BackgroundWorkerUnblockSignals();

    /*
     * We don't currently need any ResourceOwner in a walreceiver process, but
     * if we did, we could call CreateAuxProcessResourceOwner here.
     */

    /* Initialise stats to a sanish value */
    MyLogicalRepWorker->last_send_time = MyLogicalRepWorker->last_recv_time =
        MyLogicalRepWorker->reply_time = GetCurrentTimestamp();

    /* Load the libpq-specific functions */
    load_file("libpqwalreceiver", false);

    /* Run as replica session replication role. */
    SetConfigOption("session_replication_role", "replica",
                    PGC_SUSET, PGC_S_OVERRIDE);

    /* Connect to our database. */
    BackgroundWorkerInitializeConnectionByOid(MyLogicalRepWorker->dbid,
                                              MyLogicalRepWorker->userid,
                                              0);

    /* Load the subscription into persistent memory context. */
    ApplyContext = AllocSetContextCreate(TopMemoryContext,
                                         "ApplyContext",
                                         ALLOCSET_DEFAULT_SIZES);
    StartTransactionCommand();
    oldctx = MemoryContextSwitchTo(ApplyContext);

    MySubscription = GetSubscription(MyLogicalRepWorker->subid, true);
    if (!MySubscription)
    {
        ereport(LOG,
                (errmsg("logical replication apply worker for subscription %u will not "
                        "start because the subscription was removed during startup",
                        MyLogicalRepWorker->subid)));
        proc_exit(0);
    }

    MySubscriptionValid = true;
    MemoryContextSwitchTo(oldctx);

    if (!MySubscription->enabled)
    {
        ereport(LOG,
                (errmsg("logical replication apply worker for subscription \"%s\" will not "
                        "start because the subscription was disabled during startup",
                        MySubscription->name)));

        proc_exit(0);
    }

    /* Setup synchronous commit according to the user's wishes */
    SetConfigOption("synchronous_commit", MySubscription->synccommit,
                    PGC_BACKEND, PGC_S_OVERRIDE);

    /* Keep us informed about subscription changes. */
    CacheRegisterSyscacheCallback(SUBSCRIPTIONOID,
                                  subscription_change_cb,
                                  (Datum) 0);

    if (am_tablesync_worker())
        ereport(LOG,
                (errmsg("logical replication table synchronization worker for subscription \"%s\", table \"%s\" has started",
                        MySubscription->name, get_rel_name(MyLogicalRepWorker->relid))));
    else
        ereport(LOG,
                (errmsg("logical replication apply worker for subscription \"%s\" has started",
                        MySubscription->name)));

    CommitTransactionCommand();

    /* Connect to the origin and start the replication. */
    elog(DEBUG1, "connecting to publisher using connection string \"%s\"",
         MySubscription->conninfo);

    if (am_tablesync_worker())
    {
        char       *syncslotname;

        /* This is table synchronization worker, call initial sync. */
        syncslotname = LogicalRepSyncTableStart(&origin_startpos);

        /* The slot name needs to be allocated in permanent memory context. */
        oldctx = MemoryContextSwitchTo(ApplyContext);
        myslotname = pstrdup(syncslotname);
        MemoryContextSwitchTo(oldctx);

        pfree(syncslotname);
    }
    else
    {
        /* This is main apply worker */
        RepOriginId originid;
        TimeLineID  startpointTLI;
        char       *err;

        myslotname = MySubscription->slotname;

        /*
         * This shouldn't happen if the subscription is enabled, but guard
         * against DDL bugs or manual catalog changes.  (libpqwalreceiver will
         * crash if slot is NULL.)
         */
        if (!myslotname)
            ereport(ERROR,
                    (errmsg("subscription has no replication slot set")));

        /* Setup replication origin tracking. */
        StartTransactionCommand();
        snprintf(originname, sizeof(originname), "pg_%u", MySubscription->oid);
        originid = replorigin_by_name(originname, true);
        if (!OidIsValid(originid))
            originid = replorigin_create(originname);
        replorigin_session_setup(originid);
        replorigin_session_origin = originid;
        origin_startpos = replorigin_session_get_progress(false);
        CommitTransactionCommand();

        wrconn = walrcv_connect(MySubscription->conninfo, true, MySubscription->name,
                                &err);
        if (wrconn == NULL)
            ereport(ERROR,
                    (errmsg("could not connect to the publisher: %s", err)));

        /*
         * We don't really use the output identify_system for anything but it
         * does some initializations on the upstream so let's still call it.
         */
        (void) walrcv_identify_system(wrconn, &startpointTLI);

    }

    /*
     * Setup callback for syscache so that we know when something changes in
     * the subscription relation state.
     */
    CacheRegisterSyscacheCallback(SUBSCRIPTIONRELMAP,
                                  invalidate_syncing_table_states,
                                  (Datum) 0);

    /* Build logical replication streaming options. */
    options.logical = true;
    options.startpoint = origin_startpos;
    options.slotname = myslotname;
    options.proto.logical.proto_version = LOGICALREP_PROTO_VERSION_NUM;
    options.proto.logical.publication_names = MySubscription->publications;

    /* Start normal logical streaming replication. */
    walrcv_startstreaming(wrconn, &options);

    /* Run the main loop. */
    LogicalRepApplyLoop(origin_startpos);

    proc_exit(0);
}

IsLogicalWorker()

bool IsLogicalWorker

(

void

)

Definition at line 1742 of file worker.c.

References MyLogicalRepWorker.

Referenced by ProcessInterrupts().

{
    return MyLogicalRepWorker != NULL;
}