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MXS-1203: Process multiple results correctly with readwritesplit

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The readwritesplit didn't correctly process the response packets that
contained more than one part of a multi-result response. By processing the
packets in a loop, this problem is avoided.

Removed some of the more "unique" ways of sending error messages in favor
of simply writing the error to the client DCB. This removes the need for
extra logic in the clientReply response handling.
This commit is contained in:
Markus Mäkelä
2017-04-03 14:44:08 +03:00
parent d7258fffd0
commit ea38d511e3
2 changed files with 79 additions and 82 deletions
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89
server/modules/routing/readwritesplit/readwritesplit.c
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@ -605,6 +605,7 @@ static int routeQuery(MXS_ROUTER *instance, MXS_ROUTER_SESSION *router_session,
{
/** We are already processing a request from the client. Store the
* new query and wait for the previous one to complete. */
MXS_DEBUG("Storing query, expecting %d replies", rses->expected_responses);
rses->query_queue = gwbuf_append(rses->query_queue, querybuf);
querybuf = NULL;
rval = 1;
@ -711,41 +712,66 @@ static void diagnostics(MXS_ROUTER *instance, DCB *dcb)
*/
bool reply_is_complete(backend_ref_t* bref, GWBUF *buffer)
{
size_t offset = 0;
size_t len = gwbuf_length(buffer);
if (bref->reply_state == REPLY_STATE_START &&
!mxs_mysql_is_result_set(buffer))
while (offset < len)
{
/** Not a result set, we have the complete response */
LOG_RS(bref, REPLY_STATE_DONE);
bref->reply_state = REPLY_STATE_DONE;
}
else
{
int more;
int n_eof = bref->reply_state == REPLY_STATE_RSET_ROWS ? 1 : 0;
n_eof += modutil_count_signal_packets(buffer, 0, n_eof, &more);
mysql_server_cmd_t cmd = mxs_mysql_current_command(bref->bref_dcb->session);
if (n_eof == 0)
if (bref->reply_state == REPLY_STATE_START &&
!mxs_mysql_is_result_set(buffer, offset))
{
/** Waiting for the EOF packet after the column definitions */
LOG_RS(bref, REPLY_STATE_RSET_COLDEF);
bref->reply_state = REPLY_STATE_RSET_COLDEF;
}
else if (n_eof == 1 && cmd != MYSQL_COM_FIELD_LIST)
{
/** Waiting for the EOF packet after the rows */
LOG_RS(bref, REPLY_STATE_RSET_ROWS);
bref->reply_state = REPLY_STATE_RSET_ROWS;
if (!mxs_mysql_more_results_after_ok(buffer, offset))
{
/** Not a result set, we have the complete response */
LOG_RS(bref, REPLY_STATE_DONE);
bref->reply_state = REPLY_STATE_DONE;
break;
}
uint8_t header[MYSQL_HEADER_LEN];
gwbuf_copy_data(buffer, offset, sizeof(header), header);
offset += MYSQL_GET_PAYLOAD_LEN(header) + MYSQL_HEADER_LEN;
}
else
{
/** We either have a complete result set or a response to
* a COM_FIELD_LIST command */
ss_dassert(n_eof == 2 || (n_eof == 1 && cmd == MYSQL_COM_FIELD_LIST));
LOG_RS(bref, REPLY_STATE_DONE);
bref->reply_state = REPLY_STATE_DONE;
bool more = false;
int old_eof = bref->reply_state == REPLY_STATE_RSET_ROWS ? 1 : 0;
int n_eof = modutil_count_signal_packets(buffer, old_eof, &more, &offset);
mysql_server_cmd_t cmd = mxs_mysql_current_command(bref->bref_dcb->session);
if (n_eof == 0)
{
/** Waiting for the EOF packet after the column definitions */
LOG_RS(bref, REPLY_STATE_RSET_COLDEF);
bref->reply_state = REPLY_STATE_RSET_COLDEF;
}
else if (n_eof == 1 && cmd != MYSQL_COM_FIELD_LIST)
{
/** Waiting for the EOF packet after the rows */
LOG_RS(bref, REPLY_STATE_RSET_ROWS);
bref->reply_state = REPLY_STATE_RSET_ROWS;
}
else
{
/** We either have a complete result set or a response to
* a COM_FIELD_LIST command */
ss_dassert(n_eof == 2 || (n_eof == 1 && cmd == MYSQL_COM_FIELD_LIST));
LOG_RS(bref, REPLY_STATE_DONE);
bref->reply_state = REPLY_STATE_DONE;
if (more)
{
/** The server will send more resultsets */
LOG_RS(bref, REPLY_STATE_START);
bref->reply_state = REPLY_STATE_START;
}
else
{
ss_dassert(offset == len);
break;
}
}
}
}
@ -808,6 +834,11 @@ static void clientReply(MXS_ROUTER *instance,
ss_dassert(router_cli_ses->expected_responses >= 0);
ss_dassert(bref->reply_state == REPLY_STATE_DONE);
}
else
{
MXS_DEBUG("Reply not yet complete, waiting for %d replies", router_cli_ses->expected_responses);
}
/**
* Active cursor means that reply is from session command
* execution.