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MXS-1880: Fix crash after restart

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The offsets in the events were wrong if MaxScale was restarted in the
middle of a binlog. This was caused by the fact that the FDE event
contains information on binlog checksums which is required for a correct
interpretation of the binlog. The FDE event was only read when the binlog
was first opened when it needs to be read every time the binlog is opened.
This commit is contained in:
Markus Mäkelä
2018-08-15 20:23:46 +03:00
parent fb9ffdc753
commit 57334153fe
1 changed files with 47 additions and 17 deletions
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64
server/modules/routing/avrorouter/avro_file.c
View File

@ -481,6 +481,45 @@ void do_checkpoint(AVRO_INSTANCE *router, uint64_t *total_rows, uint64_t *total_
router->row_count = router->trx_count = 0;
}
void process_fde(AVRO_INSTANCE* router, uint8_t* ptr, uint32_t event_size)
{
const int BLRM_FDE_EVENT_TYPES_OFFSET = 2 + 50 + 4 + 1;
const int FDE_EXTRA_BYTES = 5;
int event_header_length = ptr[BLRM_FDE_EVENT_TYPES_OFFSET - 1];
int n_events = event_size - event_header_length - BLRM_FDE_EVENT_TYPES_OFFSET - FDE_EXTRA_BYTES;
uint8_t* checksum = ptr + event_size - event_header_length - FDE_EXTRA_BYTES;
// Precaution to prevent writing too much in case new events are added
int real_len = MXS_MIN(n_events, sizeof(router->event_type_hdr_lens));
memcpy(router->event_type_hdr_lens, ptr + BLRM_FDE_EVENT_TYPES_OFFSET, real_len);
router->event_types = n_events;
router->binlog_checksum = checksum[0];
}
bool read_fde(AVRO_INSTANCE* router)
{
bool rval = false;
uint8_t hdbuf[BINLOG_EVENT_HDR_LEN];
errno = 0; // Helps prevent false positives
if (pread(router->binlog_fd, hdbuf, BINLOG_EVENT_HDR_LEN, 4) == BINLOG_EVENT_HDR_LEN)
{
uint32_t event_size = extract_field(&hdbuf[9], 32);
uint8_t evbuf[event_size];
uint8_t event_type = hdbuf[4];
if (event_type == FORMAT_DESCRIPTION_EVENT &&
pread(router->binlog_fd, evbuf, event_size, 4 + BINLOG_EVENT_HDR_LEN) == event_size)
{
process_fde(router, evbuf, event_size);
rval = true;
}
}
return rval;
}
/**
* @brief Read all replication events from a binlog file.
*
@ -512,6 +551,13 @@ avro_binlog_end_t avro_read_all_events(AVRO_INSTANCE *router)
return AVRO_BINLOG_ERROR;
}
if (!read_fde(router))
{
MXS_ERROR("Failed to read the FDE event from the binary log: %d, %s",
errno, mxs_strerror(errno));
return AVRO_BINLOG_ERROR;
}
while (!router->service->svc_do_shutdown)
{
int n;
@ -638,24 +684,8 @@ avro_binlog_end_t avro_read_all_events(AVRO_INSTANCE *router)
hdr.event_size -= 4;
}
/* check for FORMAT DESCRIPTION EVENT */
if (hdr.event_type == FORMAT_DESCRIPTION_EVENT)
{
const int BLRM_FDE_EVENT_TYPES_OFFSET = 2 + 50 + 4 + 1;
const int FDE_EXTRA_BYTES = 5;
int event_header_length = ptr[BLRM_FDE_EVENT_TYPES_OFFSET - 1];
int n_events = hdr.event_size - event_header_length - BLRM_FDE_EVENT_TYPES_OFFSET - FDE_EXTRA_BYTES;
uint8_t* checksum = ptr + hdr.event_size - event_header_length - FDE_EXTRA_BYTES;
// Precaution to prevent writing too much in case new events are added
int real_len = MXS_MIN(n_events, sizeof(router->event_type_hdr_lens));
memcpy(router->event_type_hdr_lens, ptr + BLRM_FDE_EVENT_TYPES_OFFSET, real_len);
router->event_types = n_events;
router->binlog_checksum = checksum[0];
}
/* Decode CLOSE/STOP Event */
else if (hdr.event_type == STOP_EVENT)
if (hdr.event_type == STOP_EVENT)
{
char next_file[BLRM_BINLOG_NAME_STR_LEN + 1];
stop_seen = true;