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Initial implementation of transaction safety

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Initial implementation of transaction safety
This commit is contained in:
MassimilianoPinto
2015-08-05 14:29:17 +02:00
parent 619261cd21
commit f91a339674
5 changed files with 836 additions and 39 deletions
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343
server/modules/routing/binlog/blr_master.c
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@ -39,6 +39,7 @@
* 23/06/2015 Massimiliano Pinto Master communication goes into BLRM_SLAVE_STOPPED state
* when an error is encountered in BLRM_BINLOGDUMP state.
* Server error code and msg are reported via SHOW SLAVE STATUS
* 03/08/2015 Massimiliano Pinto Initial implementation of transaction safety
*
* @endverbatim
*/
@ -87,6 +88,7 @@ void blr_master_close(ROUTER_INSTANCE *);
static char *blr_extract_column(GWBUF *buf, int col);
void blr_cache_response(ROUTER_INSTANCE *router, char *response, GWBUF *buf);
void poll_fake_write_event(DCB *dcb);
GWBUF *blr_read_events_from_pos(ROUTER_INSTANCE *router, unsigned long long pos, REP_HEADER *hdr);
static int keepalive = 1;
/**
@ -167,7 +169,7 @@ DCB *client;
LOGIF(LM,(skygw_log_write(
LOGFILE_MESSAGE,
"%s: attempting to connect to master server %s:%d, binlog %s, pos %lu",
router->service->name, router->service->dbref->server->name, router->service->dbref->server->port, router->binlog_name, router->binlog_position)));
router->service->name, router->service->dbref->server->name, router->service->dbref->server->port, router->binlog_name, router->current_pos)));
router->connect_time = time(0);
@ -631,7 +633,7 @@ char query[128];
"%s: Request binlog records from %s at "
"position %lu from master server %s:%d",
router->service->name, router->binlog_name,
router->binlog_position,
router->current_pos,
router->service->dbref->server->name,
router->service->dbref->server->port)));
break;
@ -729,7 +731,7 @@ int len = 0x1b;
data[3] = 0; // Sequence ID
data[4] = COM_BINLOG_DUMP; // Command
encode_value(&data[5],
router->binlog_position, 32); // binlog position
router->current_pos, 32); // binlog position
encode_value(&data[9], 0, 16); // Flags
encode_value(&data[11],
router->serverid, 32); // Server-id of MaxScale
@ -842,7 +844,7 @@ int n_bufs = -1, pn_bufs = -1;
"Insufficient memory to buffer event "
"of %d bytes. Binlog %s @ %d.",
len, router->binlog_name,
router->binlog_position)));
router->current_pos)));
break;
}
@ -867,7 +869,7 @@ int n_bufs = -1, pn_bufs = -1;
"chain, but failed to create complete "
"message as expected. %s @ %d",
router->binlog_name,
router->binlog_position)));
router->current_pos)));
free(msg);
msg = NULL;
break;
@ -888,7 +890,7 @@ int n_bufs = -1, pn_bufs = -1;
LOGFILE_DEBUG,
"Residual data left after %d records. %s @ %d",
router->stats.n_binlogs,
router->binlog_name, router->binlog_position)));
router->binlog_name, router->current_pos)));
break;
}
else
@ -943,7 +945,7 @@ int n_bufs = -1, pn_bufs = -1;
"length of previous event %d. %s",
len, hdr.event_size,
router->binlog_name,
router->binlog_position,
router->current_pos,
reslen, preslen, prev_length,
(prev_length == -1 ?
(no_residual ? "No residual data from previous call" : "Residual data from previous call") : "")
@ -1000,7 +1002,7 @@ int n_bufs = -1, pn_bufs = -1;
"Closing master connection.",
router->service->name,
router->binlog_name,
router->binlog_position)));
router->current_pos)));
blr_master_close(router);
blr_master_delayed_connect(router);
return;
@ -1010,10 +1012,109 @@ int n_bufs = -1, pn_bufs = -1;
router->lastEventReceived = hdr.event_type;
router->lastEventTimestamp = hdr.timestamp;
/**
* Check for an open transaction, if the option is set
* Only complete transactions should be sent to sleves
*
* If a trasaction is pending router->last_commit_pos
* won't be updated.
*/
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == 0)) {
/* set last_commit_pos to binlog_position */
spinlock_acquire(&router->binlog_lock);
router->binlog_position = router->current_pos;
spinlock_release(&router->binlog_lock);
} else {
/**
* A transaction is pending.
* Last_commit_pos is on hold.
*
* Log a message if the transaction was opened
* at binlog router start
*/
if (router->last_written == 0) {
fprintf(stderr, "*** Router started with an Open transaction at %lu / %lu\n", router->binlog_position, router->current_pos);
}
}
// #define SHOW_EVENTS
#ifdef SHOW_EVENTS
printf("blr: event type 0x%02x, flags 0x%04x, event size %d", hdr.event_type, hdr.flags, hdr.event_size);
#endif
//fprintf(stderr, "*** binlog last_commit_pos = %lu, binlog_pos = %lu\n", router->binlog_position, router->current_pos);
/**
* Detect transactions in events
* Only complete transactions should be sent to sleves
*/
if (router->trx_safe) {
/**
* look for QUERY_EVENT [BEGIN / COMMIT] and XID_EVENT
*/
if(hdr.event_type == QUERY_EVENT) {
char *statement_sql;
int db_name_len, var_block_len, statement_len;
db_name_len = ptr[4+20+ 4 + 4];
var_block_len = ptr[4+20+ 4 + 4 + 1 + 2];
statement_len = len - (4+20+4+4+1+2+2+var_block_len+1+db_name_len);
statement_sql = calloc(1, statement_len+1);
strncpy(statement_sql, (char *)ptr+4+20+4+4+1+2+2+var_block_len+1+db_name_len, statement_len);
/* Check for BEGIN (it comes for START TRANSACTION too) */
if (strncmp(statement_sql, "BEGIN", 5) == 0) {
spinlock_acquire(&router->binlog_lock);
if (router->pending_transaction > 0) {
//fprintf(stderr, "*** A transaction is already open!!!!\n");
// stop replication ????
}
router->pending_transaction = 1;
spinlock_release(&router->binlog_lock);
//fprintf(stderr, "Transaction is starting @ %llu / %llu\n", router->binlog_position, router->current_pos);
}
/* Check for COMMIT in non transactional store engines */
if (strncmp(statement_sql, "COMMIT", 6) == 0) {
spinlock_acquire(&router->binlog_lock);
router->pending_transaction = 2;
spinlock_release(&router->binlog_lock);
//fprintf(stderr, "Transaction closed @ %llu / %llu\n", router->binlog_position, router->current_pos);
}
free(statement_sql);
}
/* Check for COMMIT in Transactional engines, i.e InnoDB */
if(hdr.event_type == XID_EVENT) {
uint64_t xid;
xid = extract_field(ptr+4+20, 64);
if (router->pending_transaction) {
spinlock_acquire(&router->binlog_lock);
router->pending_transaction = 3;
//fprintf(stderr, "Transaction XID closed @ %llu / %llu", router->binlog_position, router->current_pos);
spinlock_release(&router->binlog_lock);
}
}
}
event_limit = router->mariadb10_compat ? MAX_EVENT_TYPE_MARIADB10 : MAX_EVENT_TYPE;
if (hdr.event_type >= 0 && hdr.event_type <= event_limit)
@ -1026,7 +1127,7 @@ int n_bufs = -1, pn_bufs = -1;
"Replication fake event. "
"Binlog %s @ %d.",
router->binlog_name,
router->binlog_position)));
router->current_pos)));
router->stats.n_fakeevents++;
if (hdr.event_type == FORMAT_DESCRIPTION_EVENT)
{
@ -1071,7 +1172,7 @@ int n_bufs = -1, pn_bufs = -1;
"Replication heartbeat. "
"Binlog %s @ %d.",
router->binlog_name,
router->binlog_position)));
router->current_pos)));
router->stats.n_heartbeats++;
}
else if (hdr.flags != LOG_EVENT_ARTIFICIAL_F)
@ -1080,6 +1181,8 @@ int n_bufs = -1, pn_bufs = -1;
// into the binlog file
if (hdr.event_type == ROTATE_EVENT)
router->rotating = 1;
/* current event is being written to disk file */
if (blr_write_binlog_record(router, &hdr, ptr) == 0)
{
/*
@ -1094,6 +1197,8 @@ int n_bufs = -1, pn_bufs = -1;
blr_master_delayed_connect(router);
return;
}
/* Check for rotete event */
if (hdr.event_type == ROTATE_EVENT)
{
if (!blr_rotate_event(router, ptr, &hdr))
@ -1111,7 +1216,76 @@ int n_bufs = -1, pn_bufs = -1;
return;
}
}
blr_distribute_binlog_record(router, &hdr, ptr);
/**
* Distributing binlog events to slaves
* may depend on pending transaction
*/
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == 0)) {
spinlock_acquire(&router->binlog_lock);
router->binlog_position = router->current_pos;
spinlock_release(&router->binlog_lock);
/* Now distribute events */
blr_distribute_binlog_record(router, &hdr, ptr);
} else {
/**
* If transaction is closed:
*
* 1) read current binlog starting
* from router->last_commit_pos
*
* 2) distribute read event
*
* 3) if current pos = router->binlog_position
* update router->last_commit_pos
*
*/
if (router->pending_transaction > 1) {
unsigned long pos;
GWBUF *record;
uint8_t *raw_data;
REP_HEADER new_hdr;
int i=0;
//fprintf(stderr, "Time to feed slaves with complete transaction from %llu / %llu\n", router->binlog_position, router->current_pos);
spinlock_acquire(&router->binlog_lock);
pos = router->binlog_position;
spinlock_release(&router->binlog_lock);
while ((record = blr_read_events_from_pos(router, pos, &new_hdr)) != NULL) {
i++;
raw_data = GWBUF_DATA(record);
//fprintf(stderr, "Read event %i, last commit @ %lu / %lu. *** Distributing event: Type [%i], size %u: pos @ %llu (next is %llu)\n", i, pos, router->current_pos, new_hdr.event_type, new_hdr.event_size, router->binlog_position, new_hdr.next_pos);
/* distribute event */
blr_distribute_binlog_record(router, &new_hdr, raw_data);
spinlock_acquire(&router->binlog_lock);
pos = new_hdr.next_pos;
spinlock_release(&router->binlog_lock);
gwbuf_free(record);
}
spinlock_acquire(&router->binlog_lock);
router->binlog_position = router->current_pos;
router->pending_transaction = 0;
spinlock_release(&router->binlog_lock);
} else {
/* A transaction is still pending */
//fprintf(stderr, "A Transaction is still pending @ %llu, master is @ %llu\n", router->binlog_position, router->current_pos);
}
}
}
else
{
@ -1125,7 +1299,7 @@ int n_bufs = -1, pn_bufs = -1;
hdr.event_type,
hdr.event_size,
router->binlog_name,
router->binlog_position)));
router->current_pos)));
ptr += 5;
if (hdr.event_type == ROTATE_EVENT)
{
@ -1178,7 +1352,7 @@ int n_bufs = -1, pn_bufs = -1;
LOGIF(LE,(skygw_log_write(LOGFILE_ERROR,
"Error packet in binlog stream.%s @ %d.",
router->binlog_name,
router->binlog_position)));
router->current_pos)));
router->stats.n_binlog_errors++;
}
@ -1574,3 +1748,146 @@ char *rval;
return rval;
}
/**
* Read a replication event form current opened binlog into a GWBUF structure.
*
* @param router The router instance
* @param pos Position of binlog record to read
* @param hdr Binlog header to populate
* @return The binlog record wrapped in a GWBUF structure
*/
GWBUF
*blr_read_events_from_pos(ROUTER_INSTANCE *router, unsigned long long pos, REP_HEADER *hdr) {
unsigned long long end_pos = 0;
struct stat statb;
uint8_t hdbuf[19];
uint8_t *data;
GWBUF *result;
int n;
/* Get current binnlog position */
end_pos = router->current_pos;
/* end of file reached, we're done */
if (pos == end_pos) {
return NULL;
}
/* error */
if (pos > end_pos)
{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Error: Reading saved events, the specified pos %lu "
"is ahead of current pos %lu for file %s",
pos, router->current_pos, router->binlog_name)));
return NULL;
}
/* Read the event header information from the file */
if ((n = pread(router->binlog_fd, hdbuf, 19, pos)) != 19)
{
switch (n)
{
case 0:
LOGIF(LD, (skygw_log_write(LOGFILE_DEBUG,
"Reading saved events: reached end of binlog file at %d.", pos)));
break;
case -1:
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: failed to read binlog "
"file %s at position %d"
" (%s).", router->binlog_name,
pos, strerror(errno))));
if (errno == EBADF)
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: bad file descriptor for file %s"
", descriptor %d.",
router->binlog_name, router->binlog_fd)));
break;
default:
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: short read when reading the header. "
"Expected 19 bytes but got %d bytes. "
"Binlog file is %s, position %d",
n, router->binlog_name, pos)));
break;
}
return NULL;
}
//fprintf(stderr, "blr_read_events_from_pos read %i bytes. ptr[0]=[%i]\n", n, hdbuf[0]);
hdr->timestamp = EXTRACT32(hdbuf);
hdr->event_type = hdbuf[4];
hdr->serverid = EXTRACT32(&hdbuf[5]);
hdr->event_size = extract_field(&hdbuf[9], 32);
hdr->next_pos = EXTRACT32(&hdbuf[13]);
hdr->flags = EXTRACT16(&hdbuf[17]);
//fprintf(stderr, ">>>> event type %i\n", hdr->event_type);
//fprintf(stderr, ">>>> event size %lu\n", hdr->event_size);
//fprintf(stderr, ">>>> event next_pos %lu\n", hdr->next_pos);
/* Add MariaDB 10 checks */
if (hdr->event_type > MAX_EVENT_TYPE)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: invalid event type 0x%x. "
"Binlog file is %s, position %d",
hdr->event_type,
router->binlog_name, pos)));
return NULL;
}
if ((result = gwbuf_alloc(hdr->event_size)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: failed to allocate memory for binlog entry, "
"size %d at %d.",
hdr->event_size, pos)));
return NULL;
}
/* Copy event header*/
data = GWBUF_DATA(result);
memcpy(data, hdbuf, 19);
/* Read event data and put int into buffer after header */
if ((n = pread(router->binlog_fd, &data[19], hdr->event_size - 19, pos + 19)) != hdr->event_size - 19)
{
if (n == -1)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: the event at %ld in %s. "
"%s, expected %d bytes.",
pos, router->binlog_name,
strerror(errno), hdr->event_size - 19)));
} else {
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: short read when reading "
"the event at %ld in %s. "
"Expected %d bytes got %d bytes.",
pos, router->binlog_name, hdr->event_size - 19, n)));
if (end_pos - pos < hdr->event_size)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: binlog event "
"is close to the end of the binlog file, "
"current file size is %u.", end_pos)));
}
}
/* free buffer */
gwbuf_free(result);
return NULL;
}
// fprintf(stderr, "blr_read_events_from_pos read [%i] next bytes, raw data size is [%i]\n", n, hdr->event_size);
return result;
}