[Samba] skip chunk if "DRS linked attribute for GUID - DN not found"

[Andrej Gessel]

Hello everyone,

i try to use Samba RODC(4.6.5) with W2K8R2. Windows AD has around 35000 objects. My Samba machine is small one (ARM 32bit CPU) with only 2GB physical memory, so i can’t join to the domain because of expensive memory usage.
To solve this Problem, i decide to replicate only critical objects and then let samba_kcc to get other objects.

1 ) Is this an possible way to use Samba AD or should i replicate all objects while joining new ad?

As result i got fast join and no more problems with memory usage.
But i got some other errors for example:

../source4/dsdb/repl/replicated_objects.c:933 Failed to prepare commit of transaction: DRS linked attribute for GUID 6709d915-7dfb-41bf-b695-dd1a798d7718 - DN not found

Object with this objectGUID exists in AD, but was not replicated yet. So i create to patches follow to skip the chunks with „problem“-objects and try to get the other missing objects with effect, that links can be created and i can replicate rest.

2) Is it rigth way to raise replication on such errors? Maybe it is better to skip the chunk and replicate other stuff first and let samba_kcc do his work and repeat the skiped chunks?

Thanks,

Andrej

(patches should show the idea)

diff --git a/source4/dsdb/repl/replicated_objects.c b/source4/dsdb/repl/replicated_objects.c
index 637f7fa..a103e55 100644
--- a/source4/dsdb/repl/replicated_objects.c
+++ b/source4/dsdb/repl/replicated_objects.c
@@ -922,6 +922,18 @@ WERROR dsdb_replicated_objects_commit(struct ldb_context *ldb,
                }

               ret = ldb_transaction_prepare_commit(ldb);
+        if (ret == LDB_ERR_NO_SUCH_OBJECT) {
+                             /* restore previous schema */
+                             if (used_global_schema) {
+                                             dsdb_set_global_schema(ldb);
+                             } else if (cur_schema ) {
+                                             dsdb_reference_schema(ldb, cur_schema, false);
+                             }
+                             DEBUG(0,(__location__ " Failed to prepare commit of transaction: %s\n",
+                                             ldb_errstring(ldb)));
+                             TALLOC_FREE(tmp_ctx);
+                             return WERR_DS_NO_SUCH_OBJECT;
+             }
                if (ret != LDB_SUCCESS) {
                               /* restore previous schema */
                               if (used_global_schema) {


diff --git a/source4/dsdb/repl/drepl_out_helpers.c b/source4/dsdb/repl/drepl_out_helpers.c
index ac0b947..68774f4 100644
--- a/source4/dsdb/repl/drepl_out_helpers.c
+++ b/source4/dsdb/repl/drepl_out_helpers.c
@@ -916,7 +916,7 @@ static void dreplsrv_op_pull_source_apply_changes_trigger(struct tevent_req *req
                                                                                             &state->op->source_dsa->notify_uSN);
               talloc_free(objects);
-              if (!W_ERROR_IS_OK(status)) {
+             if (!W_ERROR_IS_OK(status) && !W_ERROR_EQUAL(status, WERR_DS_NO_SUCH_OBJECT)) {
                               /*
                               * If we failed to apply the records due to a missing
@@ -943,6 +943,11 @@ static void dreplsrv_op_pull_source_apply_changes_trigger(struct tevent_req *req
                              tevent_req_nterror(req, nt_status);
                              return;
               }
+
+             if (W_ERROR_EQUAL(status, WERR_DS_NO_SUCH_OBJECT)) {
+                /* linked value to non existing object */
+                DEBUG(0,("try to skip chunk\n"));
+        }
                if (state->op->extended_op == DRSUAPI_EXOP_NONE) {
                              /* if it applied fine, we need to update the highwatermark */
----------------------------------------------------------------------------------------------------------
Andrej Gessel (andrej.gessel at janztec.com<mailto:andrej.gessel at janztec.com>)
Software Entwicklung