hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

readwritesplit.c : router is changed so that it guarantees to keep the execution order of session commands and queries when they are routed to backend servers. In the same way it maintains the order of response packets and discards duplicate responses.

Browse Source 
For each session command a sescmd property is created and added to the end of list of session commands. List is owned by router client session and it includes all session commands from the beginning of router session.
Router maintains an individual session command cursor for each backend. A cursor refers to the first session command which the corresponding backend server haven't yet responded yet.
When response message arrives at any time from backend, first it is checked whether backend's cursor is active. Cursor is active if a session command is routed to backend and the backend haven't responded to it yet. If cursor is active, next it is checked whether the current session command property has been responded by other backend. If both are true, then response message is sent to client as is. If session command response is routed to client already, the arrived response is discarded.
This commit is contained in:
VilhoRaatikka
2014-03-16 19:43:49 +02:00
parent a3f7eebdc9
commit 90f701be8e
6 changed files with 182 additions and 211 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
server/modules/protocol/mysql_backend.c
View File

@ -567,9 +567,7 @@ gw_MySQLWrite_backend(DCB *dcb, GWBUF *queue)
/*<
* Now we set the last command received, from the current queue
*/
// memcpy(&dcb->command, &queue->command, sizeof(dcb->command));
spinlock_release(&dcb->authlock);
// LOGIF(LD, debuglog_statements(dcb, gwbuf_clone(queue)));
rc = dcb_write(dcb, queue);
return rc;
}
@ -847,7 +845,6 @@ static int gw_change_user(DCB *backend, SERVER *server, SESSION *in_session, GWB
unsigned int auth_token_len = 0;
uint8_t *auth_token = NULL;
int rv = -1;
int len = 0;
int auth_ret = 1;
current_session = (MYSQL_session *)in_session->client->data;
@ -919,7 +916,6 @@ static int gw_session(DCB *backend_dcb, void *data) {
GWBUF *queue = NULL;
queue = (GWBUF *) data;
// queue->command = ROUTER_CHANGE_SESSION;
backend_dcb->func.write(backend_dcb, queue);
return 1;