DROP ME! tests: use less partitions in rack aware placement test for …

…debug builds

Debugs builds are really slow because of default allocator and  sanitizer overhead.
Use less partitions in debug builds to make test more reliable.

Fixes: #6248

Signed-off-by: Michal Maslanka <michal@redpanda.com>

tests/rptest/tests/rack_aware_replica_placement_test.py

@@ -8,6 +8,7 @@
 # by the Apache License, Version 2.0
 
 import random
+import os
 from ducktape.utils.util import wait_until
 from ducktape.mark import matrix
 from ducktape.mark import ok_to_fail
@@ -150,6 +151,13 @@ def test_replica_placement(self, rack_layout_str, num_partitions,
         for topic in topics:
             self._validate_placement(topic, rack_layout, replication_factor)
 
+    def _partition_count(self):
+        # use smaller number of partitions for debug builds
+        if os.environ.get('BUILD_TYPE', None) == 'debug':
+            return random.randint(20, 40)
+
+        return random.randint(200, 300)
+
     @cluster(num_nodes=6)
     @matrix(rack_layout=['ABCDEF', 'xxYYzz', 'ooooFF'])
     def test_rack_awareness_after_node_operations(self, rack_layout):
@@ -168,7 +176,7 @@ def test_rack_awareness_after_node_operations(self, rack_layout):
         self.redpanda.start()
         self._client = DefaultClient(self.redpanda)
 
-        topic = TopicSpec(partition_count=random.randint(200, 300),
+        topic = TopicSpec(partition_count=self._partition_count(),
                           replication_factor=replication_factor)
         self.client().create_topic(topic)
         self._validate_placement(topic, rack_layout, replication_factor)