/*
* Initialize workspace for a worker process: create the schema if it doesn't
* already exist.
*/
static void
initialize_worker_spi(worktable *table)
{
int ret;
int ntup;
bool isnull;
StringInfoData buf;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "initializing spi_worker schema");
/* XXX could we use CREATE SCHEMA IF NOT EXISTS? */
initStringInfo(&buf);
appendStringInfo(&buf, "select count(*) from pg_namespace where nspname = '%s'",
table->schema);
ret = SPI_execute(buf.data, true, 0);
if (ret != SPI_OK_SELECT)
elog(FATAL, "SPI_execute failed: error code %d", ret);
if (SPI_processed != 1)
elog(FATAL, "not a singleton result");
ntup = DatumGetInt64(SPI_getbinval(SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1, &isnull));
if (isnull)
elog(FATAL, "null result");
if (ntup == 0)
{
resetStringInfo(&buf);
appendStringInfo(&buf,
"CREATE SCHEMA \"%s\" "
"CREATE TABLE \"%s\" ("
" type text CHECK (type IN ('total', 'delta')), "
" value integer)"
"CREATE UNIQUE INDEX \"%s_unique_total\" ON \"%s\" (type) "
"WHERE type = 'total'",
table->schema, table->name, table->name, table->name);
/* set statement start time */
SetCurrentStatementStartTimestamp();
ret = SPI_execute(buf.data, false, 0);
if (ret != SPI_OK_UTILITY)
elog(FATAL, "failed to create my schema");
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
void worker_main(Datum arg)
{
int ret;
StringInfoData buf;
uint32 segment = UInt32GetDatum(arg);
/* Setup signal handlers */
pqsignal(SIGHUP, worker_sighup);
pqsignal(SIGTERM, worker_sigterm);
/* Allow signals */
BackgroundWorkerUnblockSignals();
initialize_worker(segment);
/* Connect to the database */
BackgroundWorkerInitializeConnection(job->datname, job->rolname);
elog(LOG, "%s initialized running job id %d", MyBgworkerEntry->bgw_name, job->job_id);
pgstat_report_appname(MyBgworkerEntry->bgw_name);
/* Initialize the query text */
initStringInfo(&buf);
appendStringInfo(&buf,
"SELECT * FROM %s.%s(%d, NULL)",
job_run_function.schema,
job_run_function.name,
job->job_id);
/* Initialize the SPI subsystem */
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, buf.data);
SetCurrentStatementStartTimestamp();
/* And run the query */
ret = SPI_execute(buf.data, true, 0);
if (ret < 0)
elog(FATAL, "errors while executing %s", buf.data);
/* Commmit the transaction */
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
proc_exit(0);
}
/*
* Returns a count of the number of non-template databases from the catalog.
*/
int get_database_count(void) {
int retval, processed;
StringInfoData buf;
SPITupleTable *coltuptable;
int database_count = 0;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
initStringInfo(&buf);
appendStringInfo(&buf, "SELECT count(*) FROM pg_database WHERE datname NOT IN ('template0', 'template1') AND datallowconn IS TRUE;");
retval = SPI_execute(buf.data, false, 0);
if (retval != SPI_OK_SELECT) {
elog(FATAL, "Database information collection failed");
// FAIL RETURN 1
}
processed = SPI_processed;
if (processed > 0) {
coltuptable = SPI_tuptable;
database_count = atoi(SPI_getvalue(coltuptable->vals[0], coltuptable->tupdesc, 1));
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
return database_count;
}
/*
* Ensure that the environment is sane.
* This involves checking the Postgresql version, and if in network mode
* also establishing a connection to a receiver.
*/
int ensure_valid_environment(void) {
StringInfoData buf;
int retval;
char* pgversion;
SPITupleTable *coltuptable;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
/* Ensure compatible version */
pgstat_report_activity(STATE_RUNNING, "verifying compatible postgres version");
initStringInfo(&buf);
appendStringInfo(&buf,
"select version();"
);
retval = SPI_execute(buf.data, false, 0);
if (retval != SPI_OK_SELECT) {
elog(FATAL, "Unable to query postgres version %d", retval);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
return 1;
}
coltuptable = SPI_tuptable;
pgversion = SPI_getvalue(coltuptable->vals[0], coltuptable->tupdesc, 1);
if(strstr(pgversion, "PostgreSQL 9.3") == NULL) {
elog(FATAL, "Unsupported Postgresql version");
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
return 1;
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
/*
* Attempt to establish a connection if the output mode is network.
*/
if (strcmp(output_mode, "network") == 0) {
retval = establish_connection();
if (retval == 2) {
elog(LOG, "Error : Failed to connect to antenna please check domain is available from host.");
}
}
//TODO verify logging directory is accessible when csv mode.
elog(LOG, "Pgsampler Initialized");
return 0;
}
/*
* Make sure that we started local transaction.
*
* Also switches to ApplyMessageContext as necessary.
*/
static bool
ensure_transaction(void)
{
if (IsTransactionState())
{
SetCurrentStatementStartTimestamp();
if (CurrentMemoryContext != ApplyMessageContext)
MemoryContextSwitchTo(ApplyMessageContext);
return false;
}
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
maybe_reread_subscription();
MemoryContextSwitchTo(ApplyMessageContext);
return true;
}
static void
execute_pg_settings_logger(config_log_objects *objects) {
int ret;
bool isnull;
StringInfoData buf;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "executing configuration logger function");
initStringInfo(&buf);
appendStringInfo(
&buf,
"SELECT %s.%s()",
config_log_schema,
objects->function_name
);
ret = SPI_execute(buf.data, false, 0);
if (ret != SPI_OK_SELECT)
{
elog(FATAL, "SPI_execute failed: error code %d", ret);
}
if (SPI_processed != 1)
{
elog(FATAL, "not a singleton result");
}
log_info("pg_settings_logger() executed");
if(DatumGetBool(SPI_getbinval(SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1, &isnull)))
{
log_info("Configuration changes recorded");
}
else
{
log_info("No configuration changes detected");
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
/*
* This function will set a string in shared memory which is the name of the database to connect to
* the next time the background worker restarts. Because a bgworker can only connect to one database
* at a time, and some catalogs and stats are scoped to the current database, the bg worker
* periodically restarts to collect latest stats from another database.
*
*/
int set_next_db_target(void) {
int retval, processed;
StringInfoData buf;
SPITupleTable *coltuptable;
char* next_db_target;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
/* get sorted list of databases, find one after target_db*/
initStringInfo(&buf);
appendStringInfo(&buf,
"SELECT datname FROM pg_database WHERE datname NOT IN ('template0', 'template1') AND datallowconn IS TRUE AND datname > '%s' ORDER BY datname ASC LIMIT 1;", target_db
);
retval = SPI_execute(buf.data, false, 0);
if (retval != SPI_OK_SELECT) {
elog(FATAL, "Database information collection failed");
// FAIL RETURN 1
}
processed = SPI_processed;
if(processed == 0) {
//No matching records so pick first database.
resetStringInfo(&buf);
appendStringInfoString(&buf,
"SELECT datname FROM pg_database WHERE datname NOT IN ('template0', 'template1') AND datallowconn IS TRUE ORDER BY datname ASC LIMIT 1;"
);
retval = SPI_execute(buf.data, false, 0);
if (retval != SPI_OK_SELECT) {
elog(FATAL, "Database information collection failed");
// FAIL RETURN 1
}
}
coltuptable = SPI_tuptable;
next_db_target = SPI_getvalue(coltuptable->vals[0], coltuptable->tupdesc, 1);
// elog(LOG, "NEXTDB TARGET: %s", next_db_target); //print next target db
strcpy(pgsampler_state->next_db, next_db_target);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
return 0;
}
/* --------------------------------
* InitPostgres
* Initialize POSTGRES.
*
* The database can be specified by name, using the in_dbname parameter, or by
* OID, using the dboid parameter. In the latter case, the actual database
* name can be returned to the caller in out_dbname. If out_dbname isn't
* NULL, it must point to a buffer of size NAMEDATALEN.
*
* In bootstrap mode no parameters are used. The autovacuum launcher process
* doesn't use any parameters either, because it only goes far enough to be
* able to read pg_database; it doesn't connect to any particular database.
* In walsender mode only username is used.
*
* As of PostgreSQL 8.2, we expect InitProcess() was already called, so we
* already have a PGPROC struct ... but it's not completely filled in yet.
*
* Note:
* Be very careful with the order of calls in the InitPostgres function.
* --------------------------------
*/
void
InitPostgres(const char *in_dbname, Oid dboid, const char *username,
char *out_dbname)
{
bool bootstrap = IsBootstrapProcessingMode();
bool am_superuser;
char *fullpath;
char dbname[NAMEDATALEN];
elog(DEBUG3, "InitPostgres");
/*
* Add my PGPROC struct to the ProcArray.
*
* Once I have done this, I am visible to other backends!
*/
InitProcessPhase2();
/*
* Initialize my entry in the shared-invalidation manager's array of
* per-backend data.
*
* Sets up MyBackendId, a unique backend identifier.
*/
MyBackendId = InvalidBackendId;
SharedInvalBackendInit(false);
if (MyBackendId > MaxBackends || MyBackendId <= 0)
elog(FATAL, "bad backend ID: %d", MyBackendId);
/* Now that we have a BackendId, we can participate in ProcSignal */
ProcSignalInit(MyBackendId);
/*
* Also set up timeout handlers needed for backend operation. We need
* these in every case except bootstrap.
*/
if (!bootstrap)
{
RegisterTimeout(DEADLOCK_TIMEOUT, CheckDeadLock);
RegisterTimeout(STATEMENT_TIMEOUT, StatementTimeoutHandler);
RegisterTimeout(LOCK_TIMEOUT, LockTimeoutHandler);
}
/*
* bufmgr needs another initialization call too
*/
InitBufferPoolBackend();
/*
* Initialize local process's access to XLOG.
*/
if (IsUnderPostmaster)
{
/*
* The postmaster already started the XLOG machinery, but we need to
* call InitXLOGAccess(), if the system isn't in hot-standby mode.
* This is handled by calling RecoveryInProgress and ignoring the
* result.
*/
(void) RecoveryInProgress();
}
else
{
/*
* We are either a bootstrap process or a standalone backend. Either
* way, start up the XLOG machinery, and register to have it closed
* down at exit.
*/
StartupXLOG();
on_shmem_exit(ShutdownXLOG, 0);
}
/*
* Initialize the relation cache and the system catalog caches. Note that
* no catalog access happens here; we only set up the hashtable structure.
* We must do this before starting a transaction because transaction abort
* would try to touch these hashtables.
*/
RelationCacheInitialize();
InitCatalogCache();
InitPlanCache();
/* Initialize portal manager */
EnablePortalManager();
/* Initialize stats collection --- must happen before first xact */
if (!bootstrap)
pgstat_initialize();
/*
* Load relcache entries for the shared system catalogs. This must create
* at least entries for pg_database and catalogs used for authentication.
*/
RelationCacheInitializePhase2();
/*
* Set up process-exit callback to do pre-shutdown cleanup. This is the
* first before_shmem_exit callback we register; thus, this will be the
* last thing we do before low-level modules like the buffer manager begin
* to close down. We need to have this in place before we begin our first
* transaction --- if we fail during the initialization transaction, as is
* entirely possible, we need the AbortTransaction call to clean up.
*/
before_shmem_exit(ShutdownPostgres, 0);
/* The autovacuum launcher is done here */
if (IsAutoVacuumLauncherProcess())
return;
/*
* Start a new transaction here before first access to db, and get a
* snapshot. We don't have a use for the snapshot itself, but we're
* interested in the secondary effect that it sets RecentGlobalXmin. (This
* is critical for anything that reads heap pages, because HOT may decide
* to prune them even if the process doesn't attempt to modify any
* tuples.)
*/
if (!bootstrap)
{
/* statement_timestamp must be set for timeouts to work correctly */
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
/*
* transaction_isolation will have been set to the default by the
* above. If the default is "serializable", and we are in hot
* standby, we will fail if we don't change it to something lower.
* Fortunately, "read committed" is plenty good enough.
*/
XactIsoLevel = XACT_READ_COMMITTED;
(void) GetTransactionSnapshot();
}
/*
* Perform client authentication if necessary, then figure out our
* postgres user ID, and see if we are a superuser.
*
* In standalone mode and in autovacuum worker processes, we use a fixed
* ID, otherwise we figure it out from the authenticated user name.
*/
if (bootstrap || IsAutoVacuumWorkerProcess())
{
InitializeSessionUserIdStandalone();
am_superuser = true;
}
else if (!IsUnderPostmaster)
{
InitializeSessionUserIdStandalone();
am_superuser = true;
if (!ThereIsAtLeastOneRole())
ereport(WARNING,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("no roles are defined in this database system"),
errhint("You should immediately run CREATE USER \"%s\" SUPERUSER;.",
username)));
}
else if (IsBackgroundWorker)
{
if (username == NULL)
{
InitializeSessionUserIdStandalone();
am_superuser = true;
}
else
{
InitializeSessionUserId(username);
am_superuser = superuser();
}
}
else
{
/* normal multiuser case */
Assert(MyProcPort != NULL);
PerformAuthentication(MyProcPort);
InitializeSessionUserId(username);
am_superuser = superuser();
}
/*
* If we're trying to shut down, only superusers can connect, and new
* replication connections are not allowed.
*/
if ((!am_superuser || am_walsender) &&
MyProcPort != NULL &&
MyProcPort->canAcceptConnections == CAC_WAITBACKUP)
{
if (am_walsender)
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("new replication connections are not allowed during database shutdown")));
else
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to connect during database shutdown")));
}
/*
* Binary upgrades only allowed super-user connections
*/
if (IsBinaryUpgrade && !am_superuser)
{
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to connect in binary upgrade mode")));
}
/*
* The last few connections slots are reserved for superusers. Although
* replication connections currently require superuser privileges, we
* don't allow them to consume the reserved slots, which are intended for
* interactive use.
*/
if ((!am_superuser || am_walsender) &&
ReservedBackends > 0 &&
!HaveNFreeProcs(ReservedBackends))
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("remaining connection slots are reserved for non-replication superuser connections")));
/* Check replication permissions needed for walsender processes. */
if (am_walsender)
{
Assert(!bootstrap);
if (!superuser() && !has_rolreplication(GetUserId()))
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser or replication role to start walsender")));
}
/*
* If this is a plain walsender only supporting physical replication, we
* don't want to connect to any particular database. Just finish the
* backend startup by processing any options from the startup packet, and
* we're done.
*/
if (am_walsender && !am_db_walsender)
{
/* process any options passed in the startup packet */
if (MyProcPort != NULL)
process_startup_options(MyProcPort, am_superuser);
/* Apply PostAuthDelay as soon as we've read all options */
if (PostAuthDelay > 0)
pg_usleep(PostAuthDelay * 1000000L);
/* initialize client encoding */
InitializeClientEncoding();
/* report this backend in the PgBackendStatus array */
pgstat_bestart();
/* close the transaction we started above */
CommitTransactionCommand();
return;
}
/*
* Set up the global variables holding database id and default tablespace.
* But note we won't actually try to touch the database just yet.
*
* We take a shortcut in the bootstrap case, otherwise we have to look up
* the db's entry in pg_database.
*/
if (bootstrap)
{
MyDatabaseId = TemplateDbOid;
MyDatabaseTableSpace = DEFAULTTABLESPACE_OID;
}
else if (in_dbname != NULL)
{
HeapTuple tuple;
Form_pg_database dbform;
tuple = GetDatabaseTuple(in_dbname);
if (!HeapTupleIsValid(tuple))
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist", in_dbname)));
dbform = (Form_pg_database) GETSTRUCT(tuple);
MyDatabaseId = HeapTupleGetOid(tuple);
MyDatabaseTableSpace = dbform->dattablespace;
/* take database name from the caller, just for paranoia */
strlcpy(dbname, in_dbname, sizeof(dbname));
}
else if (OidIsValid(dboid))
{
/* caller specified database by OID */
HeapTuple tuple;
Form_pg_database dbform;
tuple = GetDatabaseTupleByOid(dboid);
if (!HeapTupleIsValid(tuple))
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database %u does not exist", dboid)));
dbform = (Form_pg_database) GETSTRUCT(tuple);
MyDatabaseId = HeapTupleGetOid(tuple);
MyDatabaseTableSpace = dbform->dattablespace;
Assert(MyDatabaseId == dboid);
strlcpy(dbname, NameStr(dbform->datname), sizeof(dbname));
/* pass the database name back to the caller */
if (out_dbname)
strcpy(out_dbname, dbname);
}
else
{
/*
* If this is a background worker not bound to any particular
* database, we're done now. Everything that follows only makes
* sense if we are bound to a specific database. We do need to
* close the transaction we started before returning.
*/
if (!bootstrap)
CommitTransactionCommand();
return;
}
/*
* Now, take a writer's lock on the database we are trying to connect to.
* If there is a concurrently running DROP DATABASE on that database, this
* will block us until it finishes (and has committed its update of
* pg_database).
*
* Note that the lock is not held long, only until the end of this startup
* transaction. This is OK since we will advertise our use of the
* database in the ProcArray before dropping the lock (in fact, that's the
* next thing to do). Anyone trying a DROP DATABASE after this point will
* see us in the array once they have the lock. Ordering is important for
* this because we don't want to advertise ourselves as being in this
* database until we have the lock; otherwise we create what amounts to a
* deadlock with CountOtherDBBackends().
*
* Note: use of RowExclusiveLock here is reasonable because we envision
* our session as being a concurrent writer of the database. If we had a
* way of declaring a session as being guaranteed-read-only, we could use
* AccessShareLock for such sessions and thereby not conflict against
* CREATE DATABASE.
*/
if (!bootstrap)
LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
RowExclusiveLock);
/*
* Now we can mark our PGPROC entry with the database ID.
*
* We assume this is an atomic store so no lock is needed; though actually
* things would work fine even if it weren't atomic. Anyone searching the
* ProcArray for this database's ID should hold the database lock, so they
* would not be executing concurrently with this store. A process looking
* for another database's ID could in theory see a chance match if it read
* a partially-updated databaseId value; but as long as all such searches
* wait and retry, as in CountOtherDBBackends(), they will certainly see
* the correct value on their next try.
*/
MyProc->databaseId = MyDatabaseId;
/*
* We established a catalog snapshot while reading pg_authid and/or
* pg_database; but until we have set up MyDatabaseId, we won't react to
* incoming sinval messages for unshared catalogs, so we won't realize it
* if the snapshot has been invalidated. Assume it's no good anymore.
*/
InvalidateCatalogSnapshot();
/*
* Recheck pg_database to make sure the target database hasn't gone away.
* If there was a concurrent DROP DATABASE, this ensures we will die
* cleanly without creating a mess.
*/
if (!bootstrap)
{
HeapTuple tuple;
tuple = GetDatabaseTuple(dbname);
if (!HeapTupleIsValid(tuple) ||
MyDatabaseId != HeapTupleGetOid(tuple) ||
MyDatabaseTableSpace != ((Form_pg_database) GETSTRUCT(tuple))->dattablespace)
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist", dbname),
errdetail("It seems to have just been dropped or renamed.")));
}
/*
* Now we should be able to access the database directory safely. Verify
* it's there and looks reasonable.
*/
fullpath = GetDatabasePath(MyDatabaseId, MyDatabaseTableSpace);
if (!bootstrap)
{
if (access(fullpath, F_OK) == -1)
{
if (errno == ENOENT)
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist",
dbname),
errdetail("The database subdirectory \"%s\" is missing.",
fullpath)));
else
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not access directory \"%s\": %m",
fullpath)));
}
ValidatePgVersion(fullpath);
}
SetDatabasePath(fullpath);
/*
* It's now possible to do real access to the system catalogs.
*
* Load relcache entries for the system catalogs. This must create at
* least the minimum set of "nailed-in" cache entries.
*/
RelationCacheInitializePhase3();
/* set up ACL framework (so CheckMyDatabase can check permissions) */
initialize_acl();
/*
* Re-read the pg_database row for our database, check permissions and set
* up database-specific GUC settings. We can't do this until all the
* database-access infrastructure is up. (Also, it wants to know if the
* user is a superuser, so the above stuff has to happen first.)
*/
if (!bootstrap)
CheckMyDatabase(dbname, am_superuser);
/*
* Now process any command-line switches and any additional GUC variable
* settings passed in the startup packet. We couldn't do this before
* because we didn't know if client is a superuser.
*/
if (MyProcPort != NULL)
process_startup_options(MyProcPort, am_superuser);
/* Process pg_db_role_setting options */
process_settings(MyDatabaseId, GetSessionUserId());
/* Apply PostAuthDelay as soon as we've read all options */
if (PostAuthDelay > 0)
pg_usleep(PostAuthDelay * 1000000L);
/*
* Initialize various default states that can't be set up until we've
* selected the active user and gotten the right GUC settings.
*/
/* set default namespace search path */
InitializeSearchPath();
/* initialize client encoding */
InitializeClientEncoding();
/* report this backend in the PgBackendStatus array */
if (!bootstrap)
pgstat_bestart();
/* close the transaction we started above */
if (!bootstrap)
CommitTransactionCommand();
}
/*
* This function receives a command names and a query and it produces a protocol valid command string
* which can be send to the server based on the format of the result set. It handles memory contexts
* appropriately, returning a pointer to the command string in the current context when called.
*
*/
char* exec_to_command(const char* command, char* q) {
StringInfoData resultbuf;
char* result;
int i, j, processed, retval;
SPITupleTable *coltuptable;
MemoryContext pre_context;
MemoryContext spi_conn_context;
// elog(LOG, "%s", command); //prints the current command running
pre_context = CurrentMemoryContext;
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
retval = SPI_execute(q, false, 0);
if (retval != SPI_OK_SELECT) {
elog(LOG, "Database SELECT execution failed: %d", retval);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
result = pstrdup("");
return result;
}
processed = SPI_processed;
coltuptable = SPI_tuptable;
initStringInfo(&resultbuf);
appendStringInfoString(&resultbuf, command);
appendStringInfoString(&resultbuf, ";"); //artisinal semicolon
if (coltuptable != NULL) {
for(i = 0; i < processed; i++) {
for(j = 1; j <= coltuptable->tupdesc->natts; j++) {
if (SPI_getvalue(coltuptable->vals[i], coltuptable->tupdesc, j) != NULL) {
appendStringInfoString(&resultbuf, SPI_getvalue(coltuptable->vals[i], coltuptable->tupdesc, j));
}
appendStringInfo(&resultbuf, FIELD_DELIMIT);
}
appendStringInfo(&resultbuf,REC_DELIMIT);
}
}
appendStringInfo(&resultbuf, CDELIMIT);
spi_conn_context = MemoryContextSwitchTo(pre_context);
result = pstrdup(resultbuf.data);
MemoryContextSwitchTo(spi_conn_context);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
return result;
}
void
worker_spi_main(Datum main_arg)
{
int index = DatumGetInt32(main_arg);
worktable *table;
StringInfoData buf;
char name[20];
table = palloc(sizeof(worktable));
sprintf(name, "schema%d", index);
table->schema = pstrdup(name);
table->name = pstrdup("counted");
/* Establish signal handlers before unblocking signals. */
pqsignal(SIGHUP, worker_spi_sighup);
pqsignal(SIGTERM, worker_spi_sigterm);
/* We're now ready to receive signals */
BackgroundWorkerUnblockSignals();
/* Connect to our database */
BackgroundWorkerInitializeConnection("postgres", NULL);
elog(LOG, "%s initialized with %s.%s",
MyBgworkerEntry->bgw_name, table->schema, table->name);
initialize_worker_spi(table);
/*
* Quote identifiers passed to us. Note that this must be done after
* initialize_worker_spi, because that routine assumes the names are not
* quoted.
*
* Note some memory might be leaked here.
*/
table->schema = quote_identifier(table->schema);
table->name = quote_identifier(table->name);
initStringInfo(&buf);
appendStringInfo(&buf,
"WITH deleted AS (DELETE "
"FROM %s.%s "
"WHERE type = 'delta' RETURNING value), "
"total AS (SELECT coalesce(sum(value), 0) as sum "
"FROM deleted) "
"UPDATE %s.%s "
"SET value = %s.value + total.sum "
"FROM total WHERE type = 'total' "
"RETURNING %s.value",
table->schema, table->name,
table->schema, table->name,
table->name,
table->name);
/*
* Main loop: do this until the SIGTERM handler tells us to terminate
*/
while (!got_sigterm)
{
int ret;
int rc;
/*
* Background workers mustn't call usleep() or any direct equivalent:
* instead, they may wait on their process latch, which sleeps as
* necessary, but is awakened if postmaster dies. That way the
* background process goes away immediately in an emergency.
*/
rc = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
worker_spi_naptime * 1000L);
ResetLatch(&MyProc->procLatch);
/* emergency bailout if postmaster has died */
if (rc & WL_POSTMASTER_DEATH)
proc_exit(1);
/*
* In case of a SIGHUP, just reload the configuration.
*/
if (got_sighup)
{
got_sighup = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* Start a transaction on which we can run queries. Note that each
* StartTransactionCommand() call should be preceded by a
* SetCurrentStatementStartTimestamp() call, which sets both the time
* for the statement we're about the run, and also the transaction
* start time. Also, each other query sent to SPI should probably be
* preceded by SetCurrentStatementStartTimestamp(), so that statement
* start time is always up to date.
*
* The SPI_connect() call lets us run queries through the SPI manager,
* and the PushActiveSnapshot() call creates an "active" snapshot
* which is necessary for queries to have MVCC data to work on.
*
* The pgstat_report_activity() call makes our activity visible
* through the pgstat views.
*/
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, buf.data);
/* We can now execute queries via SPI */
ret = SPI_execute(buf.data, false, 0);
if (ret != SPI_OK_UPDATE_RETURNING)
elog(FATAL, "cannot select from table %s.%s: error code %d",
table->schema, table->name, ret);
if (SPI_processed > 0)
{
bool isnull;
int32 val;
val = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1, &isnull));
if (!isnull)
elog(LOG, "%s: count in %s.%s is now %d",
MyBgworkerEntry->bgw_name,
table->schema, table->name, val);
}
/*
* And finish our transaction.
*/
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
proc_exit(1);
}
void
worker_test_main(Datum main_arg)
{
dsm_segment *seg;
volatile test_shm_mq_header *hdr;
PGPROC *registrant;
pqsignal(SIGHUP, handle_sighup);
pqsignal(SIGTERM, handle_sigterm);
BackgroundWorkerUnblockSignals();
printf("worker_test_main: %d\n", DatumGetInt32(main_arg));
CurrentResourceOwner = ResourceOwnerCreate(NULL, "worker test");
seg = dsm_attach(DatumGetInt32(main_arg));
if (seg == NULL)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("unable to map dynamic shared memory segment")));
hdr = dsm_segment_address(seg);
/* 開始 */
SpinLockAcquire(&hdr->mutex);
hdr->workers_ready++;
hdr->workers_attached++;
SpinLockRelease(&hdr->mutex);
registrant = BackendPidGetProc(MyBgworkerEntry->bgw_notify_pid);
if (registrant == NULL)
{
elog(DEBUG1, "registrant backend has exited prematurely");
proc_exit(1);
}
SetLatch(®istrant->procLatch);
/* Do the work */
BackgroundWorkerInitializeConnection(hdr->dbname, NULL);
printf("DSM: %p\n", dsm_segment_address);
#if 0
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "initializing spi_worker schema");
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
#endif
dsm_detach(seg);
proc_exit(0);
}
static void
ReadBlocks(int filenum)
{
FILE *file;
char record_type;
char *dbname;
Oid record_filenode;
ForkNumber record_forknum;
BlockNumber record_blocknum;
BlockNumber record_range;
int log_level = DEBUG3;
Oid relOid = InvalidOid;
Relation rel = NULL;
bool skip_relation = false;
bool skip_fork = false;
bool skip_block = false;
BlockNumber nblocks = 0;
BlockNumber blocks_restored = 0;
const char *filepath;
/*
* If this condition changes, then this code, and the code in the writer
* will need to be changed; especially the format specifiers in log and
* error messages.
*/
StaticAssertStmt(MaxBlockNumber == 0xFFFFFFFE, "Code may need review.");
filepath = getSavefileName(filenum);
file = fileOpen(filepath, PG_BINARY_R);
dbname = readDBName(file, filepath);
/*
* When restoring global objects, the dbname is zero-length string, and non-
* zero length otherwise. And filenum is never expected to be smaller than 1.
*/
Assert(filenum >= 1);
Assert(filenum == 1 ? strlen(dbname) == 0 : strlen(dbname) > 0);
/* To restore the global objects, use default database */
BackgroundWorkerInitializeConnection(filenum == 1 ? guc_default_database : dbname, NULL);
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "restoring buffers");
/*
* Note that in case of a read error, we will leak relcache entry that we may
* currently have open. In case of EOF, we close the relation after the loop.
*/
while (fileRead(&record_type, 1, file, true, filepath))
{
/*
* If we want to process the signals, this seems to be the best place
* to do it. Generally the backends refrain from processing config file
* while in transaction, but that's more for the fear of allowing GUC
* changes to affect expression evaluation, causing different results
* for the same expression in a transaction. Since this worker is not
* processing any queries, it is okay to process the config file here.
*
* Even though it's okay to process SIGHUP here, doing so doesn't add
* any value. The only reason we might want to process config file here
* would be to allow the user to interrupt the BlockReader's operation
* by changing this extenstion's GUC parameter. But the user can do that
* anyway, using SIGTERM or pg_terminate_backend().
*/
/* Stop processing the save-file if the Postmaster wants us to die. */
if (got_sigterm)
break;
ereport(log_level,
(errmsg("record type %x - %c", record_type, record_type)));
switch (record_type)
{
case 'r':
{
/* Close the previous relation, if any. */
if (rel)
{
relation_close(rel, AccessShareLock);
rel = NULL;
}
record_forknum = InvalidForkNumber;
record_blocknum = InvalidBlockNumber;
nblocks = 0;
fileRead(&record_filenode, sizeof(Oid), file, false, filepath);
relOid = GetRelOid(record_filenode);
ereport(log_level, (errmsg("processing filenode %u, relation %u",
record_filenode, relOid)));
/*
* If the relation has been rewritten/dropped since we saved it,
* just skip it and process the next relation.
*/
if (relOid == InvalidOid)
skip_relation = true;
else
{
skip_relation = false;
/* Open the relation */
rel = relation_open(relOid, AccessShareLock);
RelationOpenSmgr(rel);
}
}
break;
case 'f':
{
record_blocknum = InvalidBlockNumber;
nblocks = 0;
fileRead(&record_forknum, sizeof(ForkNumber), file, false, filepath);
if (skip_relation)
continue;
if (rel == NULL)
ereport(ERROR,
(errmsg("found a fork record without a preceeding relation record")));
ereport(log_level, (errmsg("processing fork %d", record_forknum)));
if (!smgrexists(rel->rd_smgr, record_forknum))
skip_fork = true;
else
{
skip_fork = false;
nblocks = RelationGetNumberOfBlocksInFork(rel, record_forknum);
}
}
break;
case 'b':
{
if (record_forknum == InvalidForkNumber)
ereport(ERROR,
(errmsg("found a block record without a preceeding fork record")));
fileRead(&record_blocknum, sizeof(BlockNumber), file, false, filepath);
if (skip_relation || skip_fork)
continue;
/*
* Don't try to read past the file; the file may have been shrunk
* by a vaccum/truncate operation.
*/
if (record_blocknum >= nblocks)
{
ereport(log_level,
(errmsg("reader %d skipping block filenode %u forknum %d blocknum %u",
filenum, record_filenode, record_forknum, record_blocknum)));
skip_block = true;
continue;
}
else
{
Buffer buf;
skip_block = false;
ereport(log_level,
(errmsg("reader %d reading block filenode %u forknum %d blocknum %u",
filenum, record_filenode, record_forknum, record_blocknum)));
buf = ReadBufferExtended(rel, record_forknum, record_blocknum, RBM_NORMAL, NULL);
ReleaseBuffer(buf);
++blocks_restored;
}
}
break;
case 'N':
{
BlockNumber block;
Assert(record_blocknum != InvalidBlockNumber);
if (record_blocknum == InvalidBlockNumber)
ereport(ERROR,
(errmsg("found a block range record without a preceeding block record")));
fileRead(&record_range, sizeof(int), file, false, filepath);
if (skip_relation || skip_fork || skip_block)
continue;
ereport(log_level,
(errmsg("reader %d reading range filenode %u forknum %d blocknum %u range %u",
filenum, record_filenode, record_forknum, record_blocknum, record_range)));
for (block = record_blocknum + 1; block <= (record_blocknum + record_range); ++block)
{
Buffer buf;
/*
* Don't try to read past the file; the file may have been
* shrunk by a vaccum operation.
*/
if (block >= nblocks)
{
ereport(log_level,
(errmsg("reader %d skipping block range filenode %u forknum %d start %u end %u",
filenum, record_filenode, record_forknum,
block, record_blocknum + record_range)));
break;
}
buf = ReadBufferExtended(rel, record_forknum, block, RBM_NORMAL, NULL);
ReleaseBuffer(buf);
++blocks_restored;
}
}
break;
default:
{
ereport(ERROR,
(errmsg("found unexpected save-file marker %x - %c)", record_type, record_type)));
Assert(false);
}
break;
}
}
if (rel)
relation_close(rel, AccessShareLock);
ereport(LOG,
(errmsg("Block Reader %d: restored %u blocks",
filenum, blocks_restored)));
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
fileClose(file, filepath);
/* Remove the save-file */
if (remove(filepath) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("error removing file \"%s\" : %m", filepath)));
}
static void
kill_idle_main(Datum main_arg)
{
StringInfoData buf;
/* Register functions for SIGTERM/SIGHUP management */
pqsignal(SIGHUP, kill_idle_sighup);
pqsignal(SIGTERM, kill_idle_sigterm);
/* We're now ready to receive signals */
BackgroundWorkerUnblockSignals();
/* Connect to a database */
BackgroundWorkerInitializeConnection("postgres", NULL);
/* Build query for process */
initStringInfo(&buf);
kill_idle_build_query(&buf);
while (!got_sigterm)
{
int rc, ret, i;
/* Wait necessary amount of time */
rc = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
kill_max_idle_time * 1000L,
PG_WAIT_EXTENSION);
ResetLatch(&MyProc->procLatch);
/* Emergency bailout if postmaster has died */
if (rc & WL_POSTMASTER_DEATH)
proc_exit(1);
/* Process signals */
if (got_sighup)
{
int old_interval;
/* Save old value of kill interval */
old_interval = kill_max_idle_time;
/* Process config file */
ProcessConfigFile(PGC_SIGHUP);
got_sighup = false;
ereport(LOG, (errmsg("bgworker kill_idle signal: processed SIGHUP")));
/* Rebuild query if necessary */
if (old_interval != kill_max_idle_time)
{
resetStringInfo(&buf);
initStringInfo(&buf);
kill_idle_build_query(&buf);
}
}
if (got_sigterm)
{
/* Simply exit */
ereport(LOG, (errmsg("bgworker kill_idle signal: processed SIGTERM")));
proc_exit(0);
}
/* Process idle connection kill */
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, buf.data);
/* Statement start time */
SetCurrentStatementStartTimestamp();
/* Execute query */
ret = SPI_execute(buf.data, false, 0);
/* Some error handling */
if (ret != SPI_OK_SELECT)
elog(FATAL, "Error when trying to kill idle connections");
/* Do some processing and log stuff disconnected */
for (i = 0; i < SPI_processed; i++)
{
int32 pidValue;
bool isnull;
char *datname = NULL;
char *usename = NULL;
char *client_addr = NULL;
/* Fetch values */
pidValue = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[i],
SPI_tuptable->tupdesc,
1, &isnull));
usename = DatumGetCString(SPI_getbinval(SPI_tuptable->vals[i],
SPI_tuptable->tupdesc,
3, &isnull));
datname = DatumGetCString(SPI_getbinval(SPI_tuptable->vals[i],
SPI_tuptable->tupdesc,
4, &isnull));
client_addr = DatumGetCString(SPI_getbinval(SPI_tuptable->vals[i],
SPI_tuptable->tupdesc,
5, &isnull));
/* Log what has been disconnected */
elog(LOG, "Disconnected idle connection: PID %d %s/%s/%s",
pidValue, datname ? datname : "none",
usename ? usename : "none",
client_addr ? client_addr : "none");
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
/* No problems, so clean exit */
proc_exit(0);
}
/*
* worker logic
*/
void
wed_worker_main(Datum main_arg)
{
StringInfoData buf;
/* Establish signal handlers before unblocking signals. */
pqsignal(SIGHUP, wed_worker_sighup);
pqsignal(SIGTERM, wed_worker_sigterm);
/* We're now ready to receive signals */
BackgroundWorkerUnblockSignals();
/* Connect to our database */
BackgroundWorkerInitializeConnection(wed_worker_db_name, NULL);
elog(LOG, "%s initialized in: %s",
MyBgworkerEntry->bgw_name, wed_worker_db_name);
initStringInfo(&buf);
appendStringInfo(&buf, "SELECT trcheck()");
/*
* Main loop: do this until the SIGTERM handler tells us to terminate
*/
while (!got_sigterm)
{
int ret;
int rc;
/*
* Background workers mustn't call usleep() or any direct equivalent:
* instead, they may wait on their process latch, which sleeps as
* necessary, but is awakened if postmaster dies. That way the
* background process goes away immediately in an emergency.
*/
rc = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
wed_worker_naptime * 1000L);
ResetLatch(&MyProc->procLatch);
/* emergency bailout if postmaster has died */
if (rc & WL_POSTMASTER_DEATH)
proc_exit(1);
/*
* In case of a SIGHUP, just reload the configuration.
*/
if (got_sighup)
{
got_sighup = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* Start a transaction on which we can run queries. Note that each
* StartTransactionCommand() call should be preceded by a
* SetCurrentStatementStartTimestamp() call, which sets both the time
* for the statement we're about the run, and also the transaction
* start time. Also, each other query sent to SPI should probably be
* preceded by SetCurrentStatementStartTimestamp(), so that statement
* start time is always up to date.
*
* The SPI_connect() call lets us run queries through the SPI manager,
* and the PushActiveSnapshot() call creates an "active" snapshot
* which is necessary for queries to have MVCC data to work on.
*
* The pgstat_report_activity() call makes our activity visible
* through the pgstat views.
*/
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, buf.data);
/* We can now execute queries via SPI */
ret = SPI_execute(buf.data, false, 0);
if (ret != SPI_OK_SELECT)
elog(FATAL, "stored procedure trcheck() not found: error code %d", ret);
elog(LOG, "%s : trcheck() done !", MyBgworkerEntry->bgw_name);
/*
* And finish our transaction.
*/
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
proc_exit(1);
}
static void powa_main(Datum main_arg)
{
char *q1 = "SELECT powa_take_snapshot()";
static char *q2 = "SET application_name = 'POWA collector'";
instr_time begin;
instr_time end;
long time_to_wait;
die_on_too_small_frequency();
/*
Set up signal handlers, then unblock signalsl
*/
pqsignal(SIGHUP, powa_sighup);
pqsignal(SIGTERM, powa_sigterm);
BackgroundWorkerUnblockSignals();
/*
We only connect when powa_frequency >0. If not, powa has been deactivated
*/
if (powa_frequency < 0)
{
elog(LOG, "POWA is deactivated (powa.frequency = %i), exiting",
powa_frequency);
exit(1);
}
// We got here: it means powa_frequency > 0. Let's connect
/*
Connect to POWA database
*/
BackgroundWorkerInitializeConnection(powa_database, NULL);
elog(LOG, "POWA connected to %s", powa_database);
StartTransactionCommand();
SetCurrentStatementStartTimestamp();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
SPI_execute(q2, false, 0);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
/*
let's store the current time. It will be used to
calculate a quite stable interval between each measure
*/
while (!got_sigterm)
{
/*
We can get here with a new value of powa_frequency
because of a reload. Let's suicide to disconnect
if this value is <0
*/
if (powa_frequency < 0)
{
elog(LOG, "POWA exits to disconnect from the database now");
exit(1);
}
INSTR_TIME_SET_CURRENT(begin);
ResetLatch(&MyProc->procLatch);
StartTransactionCommand();
SetCurrentStatementStartTimestamp();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
SPI_execute(q1, false, 0);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
INSTR_TIME_SET_CURRENT(end);
INSTR_TIME_SUBTRACT(end, begin);
/*
Wait powa.frequency, compensate for work time of last snapshot
*/
/*
If we got off schedule (because of a compact or delete,
just do another operation right now
*/
time_to_wait = powa_frequency - INSTR_TIME_GET_MILLISEC(end);
if (time_to_wait > 0)
{
WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
time_to_wait);
}
}
proc_exit(0);
}
static void
SaveBuffers(void)
{
int i;
int num_buffers;
int log_level = DEBUG3;
SavedBuffer *saved_buffers;
volatile BufferDesc *bufHdr; // XXX: Do we really need volatile here?
FILE *file = NULL;
int database_counter= 0;
Oid prev_database = InvalidOid;
Oid prev_filenode = InvalidOid;
ForkNumber prev_forknum = InvalidForkNumber;
BlockNumber prev_blocknum = InvalidBlockNumber;
BlockNumber range_counter = 0;
const char *savefile_path;
/*
* XXX: If the memory request fails, ask for a smaller memory chunk, and use
* it to create chunks of save-files, and make the workers read those chunks.
*
* This is not a concern as of now, so deferred; there's at least one other
* place that allocates (NBuffers * (much_bigger_struct)), so this seems to
* be an acceptable practice.
*/
saved_buffers = (SavedBuffer *) palloc(sizeof(SavedBuffer) * NBuffers);
/* Lock the buffer partitions for reading. */
for (i = 0; i < NUM_BUFFER_PARTITIONS; ++i)
LWLockAcquire(FirstBufMappingLock + i, LW_SHARED);
/* Scan and save a list of valid buffers. */
for (num_buffers = 0, i = 0, bufHdr = BufferDescriptors; i < NBuffers; ++i, ++bufHdr)
{
/* Lock each buffer header before inspecting. */
LockBufHdr(bufHdr);
/* Skip invalid buffers */
if ((bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID))
{
saved_buffers[num_buffers].database = bufHdr->tag.rnode.dbNode;
saved_buffers[num_buffers].filenode = bufHdr->tag.rnode.relNode;
saved_buffers[num_buffers].forknum = bufHdr->tag.forkNum;
saved_buffers[num_buffers].blocknum = bufHdr->tag.blockNum;
++num_buffers;
}
UnlockBufHdr(bufHdr);
}
/* Unlock the buffer partitions in reverse order, to avoid a deadlock. */
for (i = NUM_BUFFER_PARTITIONS - 1; i >= 0; --i)
LWLockRelease(FirstBufMappingLock + i);
/*
* Sort the list, so that we can optimize the storage of these buffers.
*
* The side-effect of this storage optimization is that when reading the
* blocks back from relation forks, it leads to sequential reads, which
* improve the restore speeds quite considerably as compared to random reads
* from different blocks all over the data directory.
*/
pg_qsort(saved_buffers, num_buffers, sizeof(SavedBuffer), SavedBufferCmp);
/* Connect to the database and start a transaction for database name lookups. */
BackgroundWorkerInitializeConnection(guc_default_database, NULL);
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "saving buffers");
for (i = 0; i < num_buffers; ++i)
{
int j;
SavedBuffer *buf = &saved_buffers[i];
if (i == 0)
{
/*
* Special case for global objects. The sort brings them to the
* front of the list.
*/
/* Make sure the first buffer we save belongs to global object. */
Assert(buf->database == InvalidOid);
/*
* Database number (and save-file name) 1 is reserverd for storing
* list of buffers of global objects.
*/
database_counter = 1;
savefile_path = getSavefileName(database_counter);
file = fileOpen(savefile_path, PG_BINARY_W);
writeDBName("", file, savefile_path);
prev_database = buf->database;
}
if (buf->database != prev_database)
{
char *dbname;
/*
* We are beginning to process a different database than the
* previous one; close the save-file of previous database, and open
* a new one.
*/
++database_counter;
dbname = get_database_name(buf->database);
Assert(dbname != NULL);
if (file != NULL)
fileClose(file, savefile_path);
savefile_path = getSavefileName(database_counter);
file = fileOpen(savefile_path, PG_BINARY_W);
writeDBName(dbname, file, savefile_path);
pfree(dbname);
/* Reset trackers appropriately */
prev_database = buf->database;
prev_filenode = InvalidOid;
prev_forknum = InvalidForkNumber;
prev_blocknum = InvalidBlockNumber;
range_counter = 0;
}
if (buf->filenode != prev_filenode)
{
/* We're beginning to process a new relation; emit a record for it. */
fileWrite("r", 1, file, savefile_path);
fileWrite(&(buf->filenode), sizeof(Oid), file, savefile_path);
/* Reset trackers appropriately */
prev_filenode = buf->filenode;
prev_forknum = InvalidForkNumber;
prev_blocknum = InvalidBlockNumber;
range_counter = 0;
}
if (buf->forknum != prev_forknum)
{
/*
* We're beginning to process a new fork of this relation; add a
* record for it.
*/
fileWrite("f", 1, file, savefile_path);
fileWrite(&(buf->forknum), sizeof(ForkNumber), file, savefile_path);
/* Reset trackers appropriately */
prev_forknum = buf->forknum;
prev_blocknum = InvalidBlockNumber;
range_counter = 0;
}
ereport(log_level,
(errmsg("writer: writing block db %d filenode %d forknum %d blocknum %d",
database_counter, prev_filenode, prev_forknum, buf->blocknum)));
fileWrite("b", 1, file, savefile_path);
fileWrite(&(buf->blocknum), sizeof(BlockNumber), file, savefile_path);
prev_blocknum = buf->blocknum;
/*
* If a continuous range of blocks follows this block, then emit one
* entry for the range, instead of one for each block.
*/
range_counter = 0;
for ( j = i+1; j < num_buffers; ++j)
{
SavedBuffer *tmp = &saved_buffers[j];
if (tmp->database == prev_database
&& tmp->filenode == prev_filenode
&& tmp->forknum == prev_forknum
&& tmp->blocknum == (prev_blocknum + range_counter + 1))
{
++range_counter;
}
}
if (range_counter != 0)
{
ereport(log_level,
(errmsg("writer: writing range db %d filenode %d forknum %d blocknum %d range %d",
database_counter, prev_filenode, prev_forknum, prev_blocknum, range_counter)));
fileWrite("N", 1, file, savefile_path);
fileWrite(&range_counter, sizeof(range_counter), file, savefile_path);
i += range_counter;
}
}
ereport(LOG,
(errmsg("Buffer Saver: saved metadata of %d blocks", num_buffers)));
Assert(file != NULL);
fileClose(file, savefile_path);
pfree(saved_buffers);
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
}
static config_log_objects *
initialize_objects(void)
{
config_log_objects *objects;
int ret;
int ntup;
bool isnull;
StringInfoData buf;
objects = palloc(sizeof(config_log_objects));
objects->table_name = pstrdup("pg_settings_log");
objects->function_name = pstrdup("pg_settings_logger");
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
pgstat_report_activity(STATE_RUNNING, "Verifying config log objects");
initStringInfo(&buf);
appendStringInfo(
&buf,
"SELECT COUNT(*)\
FROM information_schema.tables\
WHERE table_schema='%s'\
AND table_name ='%s'\
AND table_type='BASE TABLE'",
config_log_schema,
objects->table_name
);
ret = SPI_execute(buf.data, true, 0);
if (ret != SPI_OK_SELECT)
{
ereport(FATAL,
(errmsg("SPI_execute failed: SPI error code %d", ret)
));
}
/* This should never happen */
if (SPI_processed != 1)
{
elog(FATAL, "not a singleton result");
}
ntup = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1, &isnull));
/* This should never happen */
if (isnull)
{
elog(FATAL, "null result");
}
if (ntup == 0)
{
ereport(FATAL,
(
errmsg("Expected config log table '%s.%s' not found", config_log_schema,
objects->table_name),
errhint("Ensure superuser search_path includes the schema used by config_log; "
"check config_log.* GUC settings")
));
}
/* check function pg_settings_logger() exists */
resetStringInfo(&buf);
appendStringInfo(
&buf,
"SELECT COUNT(*) FROM pg_catalog.pg_proc p \
INNER JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace \
WHERE p.proname='%s' \
AND n.nspname='%s' \
AND p.pronargs = 0",
objects->function_name,
config_log_schema
);
ret = SPI_execute(buf.data, true, 0);
if (ret != SPI_OK_SELECT)
{
ereport(FATAL,
(errmsg("SPI_execute failed: SPI error code %d", ret)));
}
if (SPI_processed != 1)
{
elog(FATAL, "not a singleton result");
}
ntup = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1, &isnull));
if (isnull)
{
elog(FATAL, "null result");
}
if (ntup == 0)
{
ereport(FATAL,
(
errmsg("Expected config log function '%s.%s' not found", config_log_schema,
objects->function_name),
errhint("Ensure superuser search_path includes the schema used by config_log; "
"check config_log.* GUC settings")
));
}
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
pgstat_report_activity(STATE_IDLE, NULL);
log_info("initialized, database objects validated");
/* execute pg_settings_logger() here to catch any settings which have changed after server restart */
execute_pg_settings_logger(objects);
return objects;
}
