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Simplify error handling

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The error handlers are now simpler as the Backend class handles the
closing of the connections.
This commit is contained in:
Markus Mäkelä 2017-03-28 23:38:07 +03:00
parent a3396a06b8
commit c59ed30da1
2 changed files with 13 additions and 53 deletions
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64
server/modules/routing/schemarouter/schemaroutersession.cc
View File

@ -597,11 +597,6 @@ void SchemaRouterSession::handleError(GWBUF* pMessage,
{
ss_dassert(pProblem->dcb_role == DCB_ROLE_BACKEND_HANDLER);
CHK_DCB(pProblem);
MXS_SESSION *session = pProblem->session;
ss_dassert(session);
CHK_SESSION(session);
SBackend bref = get_bref_from_dcb(pProblem);
if (bref.get() == NULL) // Should never happen
@ -612,11 +607,21 @@ void SchemaRouterSession::handleError(GWBUF* pMessage,
switch (action)
{
case ERRACT_NEW_CONNECTION:
*pSuccess = handle_error_new_connection(bref, pMessage);
if (BREF_IS_WAITING_RESULT(bref))
{
/** If the client is waiting for a reply, send an error. */
m_client->func.write(m_client, gwbuf_clone(pMessage));
}
*pSuccess = have_servers();
break;
case ERRACT_REPLY_CLIENT:
handle_error_reply_client(bref, pMessage);
if (m_client->session->state == SESSION_STATE_ROUTER_READY)
{
m_client->func.write(m_client, gwbuf_clone(pMessage));
}
*pSuccess = false; /*< no new backend servers were made available */
break;
@ -625,7 +630,7 @@ void SchemaRouterSession::handleError(GWBUF* pMessage,
break;
}
dcb_close(pProblem);
bref->close();
}
/**
@ -781,17 +786,6 @@ bool SchemaRouterSession::route_session_write(GWBUF* querybuf, uint8_t command)
return succp;
}
void SchemaRouterSession::handle_error_reply_client(SBackend& bref, GWBUF* errmsg)
{
bref->clear_state(BREF_IN_USE);
bref->set_state(BREF_CLOSED);
if (m_client->session->state == SESSION_STATE_ROUTER_READY)
{
m_client->func.write(m_client, gwbuf_clone(errmsg));
}
}
/**
* Check if a router session has servers in use
* @param rses Router client session
@ -811,38 +805,6 @@ bool SchemaRouterSession::have_servers()
return false;
}
/**
* Check if there is backend reference pointing at failed DCB, and reset its
* flags. Then clear DCB's callback and finally try to reconnect.
*
* This must be called with router lock.
*
* @param inst router instance
* @param rses router client session
* @param dcb failed DCB
* @param errmsg error message which is sent to client if it is waiting
*
* @return true if there are enough backend connections to continue, false if not
*/
bool SchemaRouterSession::handle_error_new_connection(SBackend& bref, GWBUF* errmsg)
{
if (BREF_IS_WAITING_RESULT(bref))
{
/**
* If query was sent through the bref and it is waiting for reply from
* the backend server it is necessary to send an error to the client
* because it is waiting for reply.
*/
m_client->func.write(m_client, gwbuf_clone(errmsg));
bref->clear_state(BREF_WAITING_RESULT);
}
bref->clear_state(BREF_IN_USE);
bref->set_state(BREF_CLOSED);
return have_servers();
}
/**
* Finds out if there is a backend reference pointing at the DCB given as
* parameter.

2
server/modules/routing/schemarouter/schemaroutersession.hh
View File

@ -127,8 +127,6 @@ private:
SBackend get_bref_from_dcb(DCB* dcb);
bool get_shard_dcb(DCB** dcb, char* name);
bool handle_default_db();
bool handle_error_new_connection(SBackend& bref, GWBUF* errmsg);
void handle_error_reply_client(SBackend& bref, GWBUF* errmsg);
bool have_servers();
bool route_session_write(GWBUF* querybuf, uint8_t command);
bool send_database_list();