rein@OpenLDAP.org wrote:

Full_Name: Rein Tollevik Version: CVS head OS: URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (81.93.160.250) Submitted by: rein

When syncrepl and syncprov are both used on a glue database, the contextCSN received from the syncrepl producers are not passed on to the syncprov consumers when changes in subordinate databases are received. The reason is that syncrepl queues the CSNs in the glue backend, while syncprov fetches them from the backend where the changes are made. As a consequence, the consumers will be passed a cookie without any csn value.

My first attempt at fixing this was to change syncprov to fetch the queued csn values from the glue backend where it was used. But that failed as other modules queues the csn values in their own backend when they changes things.

What other modules? Generally there cannot be any other sources of changes.

Instead I changed ctxcsn.c so that it always queues them in the glue backend where syncprov is used. But I don't feel that my understanding of this stuff is good enough to be sure that this is the optimal solution..

I definitely don't like references to the syncprov overlay appearing in main slapd code like that. We need a different solution.

At one point in the past, I had changed syncrepl.c to queue the CSNs in both places, but that seemed rather sloppy. Still, it may work best here.

Btw, in syncprov_checkpoint() there is a similar SLAP_GLUE_SUBORDINATE test, should that have included an overlay_is_inst() clause as well?

Perhaps. You would have to use op->o_bd->bd_self instead of op->o_bd on that call.

Rein Tollevik Basefarm AS

Index: OpenLDAP/servers/slapd/ctxcsn.c diff -u OpenLDAP/servers/slapd/ctxcsn.c:1.1.1.11 OpenLDAP/servers/slapd/ctxcsn.c:1.2 --- OpenLDAP/servers/slapd/ctxcsn.c:1.1.1.11 Sat Mar 22 16:47:49 2008 +++ OpenLDAP/servers/slapd/ctxcsn.c Wed Apr 30 19:44:25 2008 @@ -37,67 +37,78 @@ ) { struct slap_csn_entry *csne, *committed_csne = NULL;

• Backend *be = op->o_bd;

  if ( maxcsn ) { BER_BVZERO( maxcsn ); }

• ldap_pvt_thread_mutex_lock( op->o_bd->be_pcl_mutexp );

• if ( SLAP_GLUE_SUBORDINATE( be )&& !overlay_is_inst( be, "syncprov" ))

• be = select_backend(&be->be_nsuffix[0], 1 );
  

• ldap_pvt_thread_mutex_lock( be->be_pcl_mutexp );

• LDAP_TAILQ_FOREACH( csne, op->o_bd->be_pending_csn_list, ce_csn_link ) {

• LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) { if ( csne->ce_opid == op->o_opid&& csne->ce_connid == op->o_connid ) { csne->ce_state = SLAP_CSN_COMMIT; break; } }

• LDAP_TAILQ_FOREACH( csne, op->o_bd->be_pending_csn_list, ce_csn_link ) {

• LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) { if ( csne->ce_state == SLAP_CSN_COMMIT ) committed_csne = csne; if ( csne->ce_state == SLAP_CSN_PENDING ) break; }

  if ( committed_csne&& maxcsn ) *maxcsn = committed_csne->ce_csn;

• ldap_pvt_thread_mutex_unlock( op->o_bd->be_pcl_mutexp );

• ldap_pvt_thread_mutex_unlock( be->be_pcl_mutexp ); }

  void slap_rewind_commit_csn( Operation *op ) { struct slap_csn_entry *csne;

• Backend *be = op->o_bd;

• ldap_pvt_thread_mutex_lock( op->o_bd->be_pcl_mutexp );

• if ( SLAP_GLUE_SUBORDINATE( be )&& !overlay_is_inst( be, "syncprov" ))

• be = select_backend(&be->be_nsuffix[0], 1 );
  

• ldap_pvt_thread_mutex_lock( be->be_pcl_mutexp );

• LDAP_TAILQ_FOREACH( csne, op->o_bd->be_pending_csn_list, ce_csn_link ) {

• LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) { if ( csne->ce_opid == op->o_opid&& csne->ce_connid == op->o_connid ) { csne->ce_state = SLAP_CSN_PENDING; break; } }

• ldap_pvt_thread_mutex_unlock( op->o_bd->be_pcl_mutexp );

• ldap_pvt_thread_mutex_unlock( be->be_pcl_mutexp ); }

  void slap_graduate_commit_csn( Operation *op ) { struct slap_csn_entry *csne;

• Backend *be;

  if ( op == NULL ) return; if ( op->o_bd == NULL ) return;

• be = op->o_bd;

• if ( SLAP_GLUE_SUBORDINATE( be )&& !overlay_is_inst( be, "syncprov" ))

• be = select_backend(&be->be_nsuffix[0], 1 );
  

• #if 0 /* it is NULL when we get here from the frontendDB;

  • alternate fix: initialize frontendDB like all other backends */

• assert( op->o_bd->be_pcl_mutexp != NULL );

• assert( be->be_pcl_mutexp != NULL ); #endif

• if ( op->o_bd->be_pcl_mutexp == NULL ) return;

• if ( be->be_pcl_mutexp == NULL ) return;

• ldap_pvt_thread_mutex_lock( op->o_bd->be_pcl_mutexp );

• ldap_pvt_thread_mutex_lock( be->be_pcl_mutexp );

• LDAP_TAILQ_FOREACH( csne, op->o_bd->be_pending_csn_list, ce_csn_link ) {

• LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) { if ( csne->ce_opid == op->o_opid&& csne->ce_connid == op->o_connid ) {

• 	LDAP_TAILQ_REMOVE( op->o_bd->be_pending_csn_list,
  

• 	LDAP_TAILQ_REMOVE( be->be_pending_csn_list,
  	csne, ce_csn_link );
  Debug( LDAP_DEBUG_SYNC, "slap_graduate_commit_csn: removing %p %s\n",
  	csne->ce_csn.bv_val, csne->ce_csn.bv_val, 0 );
  

@@ -110,7 +121,7 @@ } }

• ldap_pvt_thread_mutex_unlock( op->o_bd->be_pcl_mutexp );

• ldap_pvt_thread_mutex_unlock( be->be_pcl_mutexp );

  return; }

@@ -161,22 +172,25 @@ struct berval *csn ) { struct slap_csn_entry *pending;

• Backend *be = op->o_bd;

  pending = (struct slap_csn_entry *) ch_calloc( 1, sizeof( struct slap_csn_entry ));

  Debug( LDAP_DEBUG_SYNC, "slap_queue_csn: queing %p %s\n", csn->bv_val,

csn->bv_val, 0 );

• ldap_pvt_thread_mutex_lock( op->o_bd->be_pcl_mutexp );

• if ( SLAP_GLUE_SUBORDINATE( be )&& !overlay_is_inst( be, "syncprov" ))

• be = select_backend(&be->be_nsuffix[0], 1 );
  

• ldap_pvt_thread_mutex_lock( be->be_pcl_mutexp );

  ber_dupbv(&pending->ce_csn, csn ); ber_bvreplace_x(&op->o_csn,&pending->ce_csn, op->o_tmpmemctx ); pending->ce_connid = op->o_connid; pending->ce_opid = op->o_opid; pending->ce_state = SLAP_CSN_PENDING;

• LDAP_TAILQ_INSERT_TAIL( op->o_bd->be_pending_csn_list,

• LDAP_TAILQ_INSERT_TAIL( be->be_pending_csn_list, pending, ce_csn_link );

• ldap_pvt_thread_mutex_unlock( op->o_bd->be_pcl_mutexp );

• ldap_pvt_thread_mutex_unlock( be->be_pcl_mutexp ); }

  int