diff --git a/src/test/regress/bin/normalize.sed b/src/test/regress/bin/normalize.sed
index 329d63722..2c15915a2 100644
--- a/src/test/regress/bin/normalize.sed
+++ b/src/test/regress/bin/normalize.sed
@@ -219,6 +219,20 @@ s/^(ERROR:  child table is missing constraint "\w+)_([0-9])+"/\1_xxxxxx"/g
     }
 }
 
+# normalize for random waits for CREATE INDEX CONCURRENTLY isolation tests.
+# <waiting ...> outputs can be in separate lines, or on the same line, and hence
+# we have a slightly more complex pattern.
+# All the flaky tests use a index name that starts with `flaky` so we limit the
+# normalization using that pattern.
+/CREATE INDEX CONCURRENTLY flaky/ {
+	N; s/ <waiting ...>//
+}
+
+# Remove completion lines in isolation tests for CREATE INDEX CONCURRENTLY commands.
+# This is needed because the commands that are executed on the shards can block each other
+# for a small window of time and we may see the completion output in different lines.
+/step s2-flaky.* <... completed>/d
+
 # normalize long table shard name errors for alter_table_set_access_method and alter_distributed_table
 s/^(ERROR:  child table is missing constraint "\w+)_([0-9])+"/\1_xxxxxx"/g
 s/^(DEBUG:  the name of the shard \(abcde_01234567890123456789012345678901234567890_f7ff6612)_([0-9])+/\1_xxxxxx/g
diff --git a/src/test/regress/expected/isolation_drop_alter_index_select_for_update_on_mx.out b/src/test/regress/expected/isolation_drop_alter_index_select_for_update_on_mx.out
index 1db575034..38e185202 100644
--- a/src/test/regress/expected/isolation_drop_alter_index_select_for_update_on_mx.out
+++ b/src/test/regress/expected/isolation_drop_alter_index_select_for_update_on_mx.out
@@ -235,7 +235,7 @@ restore_isolation_tester_func
 (1 row)
 
 
-starting permutation: s1-start-session-level-connection s1-begin-on-worker s1-select-for-update s2-coordinator-create-index-concurrently s1-commit-worker s1-stop-connection
+starting permutation: s1-start-session-level-connection s1-begin-on-worker s1-select-for-update s2-flaky-coordinator-create-index-concurrently s1-commit-worker s1-stop-connection
 step s1-start-session-level-connection:
         SELECT start_session_level_connection_to_node('localhost', 57637);
 
@@ -260,8 +260,8 @@ run_commands_on_session_level_connection_to_node
 
 (1 row)
 
-step s2-coordinator-create-index-concurrently:
- CREATE INDEX CONCURRENTLY dist_table_index_conc ON dist_table(id);
+step s2-flaky-coordinator-create-index-concurrently:
+ CREATE INDEX CONCURRENTLY flaky_dist_table_index_conc ON dist_table(id);
 
 step s1-commit-worker:
  SELECT run_commands_on_session_level_connection_to_node('COMMIT');
diff --git a/src/test/regress/expected/isolation_hash_copy_vs_all.out b/src/test/regress/expected/isolation_hash_copy_vs_all.out
index 9e2393ae0..bbf9e9c6b 100644
--- a/src/test/regress/expected/isolation_hash_copy_vs_all.out
+++ b/src/test/regress/expected/isolation_hash_copy_vs_all.out
@@ -317,7 +317,7 @@ restore_isolation_tester_func
 (1 row)
 
 
-starting permutation: s1-initialize s1-begin s1-copy s2-ddl-create-index-concurrently s1-commit s1-select-count s1-show-indexes
+starting permutation: s1-initialize s1-begin s1-copy s2-flaky-ddl-create-index-concurrently s1-commit s1-select-count s1-show-indexes
 create_distributed_table
 ---------------------------------------------------------------------
 
@@ -326,9 +326,8 @@ create_distributed_table
 step s1-initialize: COPY hash_copy FROM PROGRAM 'echo 0, a, 0 && echo 1, b, 1 && echo 2, c, 2 && echo 3, d, 3 && echo 4, e, 4' WITH CSV;
 step s1-begin: BEGIN;
 step s1-copy: COPY hash_copy FROM PROGRAM 'echo 5, f, 5 && echo 6, g, 6 && echo 7, h, 7 && echo 8, i, 8 && echo 9, j, 9' WITH CSV;
-step s2-ddl-create-index-concurrently: CREATE INDEX CONCURRENTLY hash_copy_index ON hash_copy(id); <waiting ...>
+step s2-flaky-ddl-create-index-concurrently: CREATE INDEX CONCURRENTLY flaky_hash_copy_index ON hash_copy(id);
 step s1-commit: COMMIT;
-step s2-ddl-create-index-concurrently: <... completed>
 step s1-select-count: SELECT COUNT(*) FROM hash_copy;
 count
 ---------------------------------------------------------------------
diff --git a/src/test/regress/expected/isolation_reference_copy_vs_all.out b/src/test/regress/expected/isolation_reference_copy_vs_all.out
index c73cc3031..b7703be8e 100644
--- a/src/test/regress/expected/isolation_reference_copy_vs_all.out
+++ b/src/test/regress/expected/isolation_reference_copy_vs_all.out
@@ -319,7 +319,7 @@ restore_isolation_tester_func
 (1 row)
 
 
-starting permutation: s1-initialize s1-begin s1-copy s2-ddl-create-index-concurrently s1-commit s1-select-count s1-show-indexes
+starting permutation: s1-initialize s1-begin s1-copy s2-flaky-ddl-create-index-concurrently s1-commit s1-select-count s1-show-indexes
 create_reference_table
 ---------------------------------------------------------------------
 
@@ -328,9 +328,8 @@ create_reference_table
 step s1-initialize: COPY reference_copy FROM PROGRAM 'echo 0, a, 0 && echo 1, b, 1 && echo 2, c, 2 && echo 3, d, 3 && echo 4, e, 4' WITH CSV;
 step s1-begin: BEGIN;
 step s1-copy: COPY reference_copy FROM PROGRAM 'echo 5, f, 5  && echo 6, g, 6 && echo 7, h, 7 && echo 8, i, 8 && echo 9, j, 9' WITH CSV;
-step s2-ddl-create-index-concurrently: CREATE INDEX CONCURRENTLY reference_copy_index ON reference_copy(id); <waiting ...>
+step s2-flaky-ddl-create-index-concurrently: CREATE INDEX CONCURRENTLY flaky_reference_copy_index ON reference_copy(id);
 step s1-commit: COMMIT;
-step s2-ddl-create-index-concurrently: <... completed>
 step s1-select-count: SELECT COUNT(*) FROM reference_copy;
 count
 ---------------------------------------------------------------------
diff --git a/src/test/regress/expected/isolation_select_vs_all_on_mx.out b/src/test/regress/expected/isolation_select_vs_all_on_mx.out
index b3e529b3b..90c296404 100644
--- a/src/test/regress/expected/isolation_select_vs_all_on_mx.out
+++ b/src/test/regress/expected/isolation_select_vs_all_on_mx.out
@@ -515,7 +515,7 @@ restore_isolation_tester_func
 (1 row)
 
 
-starting permutation: s1-start-session-level-connection s1-begin-on-worker s1-disable-binary-protocol-on-worker s1-select s2-coordinator-create-index-concurrently s1-commit-worker s1-stop-connection
+starting permutation: s1-start-session-level-connection s1-begin-on-worker s1-disable-binary-protocol-on-worker s1-select s2-flaky-coordinator-create-index-concurrently s1-commit-worker s1-stop-connection
 step s1-start-session-level-connection:
         SELECT start_session_level_connection_to_node('localhost', 57637);
 
@@ -549,8 +549,8 @@ run_commands_on_session_level_connection_to_node
 
 (1 row)
 
-step s2-coordinator-create-index-concurrently:
- CREATE INDEX CONCURRENTLY select_table_index ON select_table(id);
+step s2-flaky-coordinator-create-index-concurrently:
+ CREATE INDEX CONCURRENTLY flaky_select_table_index ON select_table(id);
 
 step s1-commit-worker:
  SELECT run_commands_on_session_level_connection_to_node('COMMIT');
diff --git a/src/test/regress/spec/isolation_drop_alter_index_select_for_update_on_mx.spec b/src/test/regress/spec/isolation_drop_alter_index_select_for_update_on_mx.spec
index 089ec473e..032bf0d02 100644
--- a/src/test/regress/spec/isolation_drop_alter_index_select_for_update_on_mx.spec
+++ b/src/test/regress/spec/isolation_drop_alter_index_select_for_update_on_mx.spec
@@ -89,9 +89,9 @@ step "s2-select-for-update"
 	SELECT run_commands_on_session_level_connection_to_node('SELECT * FROM dist_table WHERE id = 5 FOR UPDATE');
 }
 
-step "s2-coordinator-create-index-concurrently"
+step "s2-flaky-coordinator-create-index-concurrently"
 {
-	CREATE INDEX CONCURRENTLY dist_table_index_conc ON dist_table(id);
+	CREATE INDEX CONCURRENTLY flaky_dist_table_index_conc ON dist_table(id);
 }
 
 step "s2-commit-worker"
@@ -117,4 +117,4 @@ step "s3-select-count"
 permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-insert" "s2-start-session-level-connection" "s2-begin-on-worker" "s2-alter" "s1-commit-worker" "s2-commit-worker" "s1-stop-connection" "s2-stop-connection" "s3-select-count"
 permutation "s1-begin" "s1-index" "s2-start-session-level-connection" "s2-begin-on-worker" "s2-select-for-update" "s1-commit" "s2-commit-worker" "s2-stop-connection"
 permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select-for-update" "s2-start-session-level-connection" "s2-begin-on-worker" "s2-select-for-update" "s1-commit-worker" "s2-commit-worker" "s1-stop-connection" "s2-stop-connection"
-permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select-for-update" "s2-coordinator-create-index-concurrently" "s1-commit-worker" "s1-stop-connection"
+permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select-for-update" "s2-flaky-coordinator-create-index-concurrently" "s1-commit-worker" "s1-stop-connection"
diff --git a/src/test/regress/spec/isolation_hash_copy_vs_all.spec b/src/test/regress/spec/isolation_hash_copy_vs_all.spec
index d7174b0cc..58ec28f5c 100644
--- a/src/test/regress/spec/isolation_hash_copy_vs_all.spec
+++ b/src/test/regress/spec/isolation_hash_copy_vs_all.spec
@@ -78,7 +78,7 @@ step "s2-truncate" { TRUNCATE hash_copy; }
 step "s2-drop" { DROP TABLE hash_copy; }
 step "s2-ddl-create-index" { CREATE INDEX hash_copy_index ON hash_copy(id); }
 step "s2-ddl-drop-index" { DROP INDEX hash_copy_index; }
-step "s2-ddl-create-index-concurrently" { CREATE INDEX CONCURRENTLY hash_copy_index ON hash_copy(id); }
+step "s2-flaky-ddl-create-index-concurrently" { CREATE INDEX CONCURRENTLY flaky_hash_copy_index ON hash_copy(id); }
 step "s2-ddl-add-column" { ALTER TABLE hash_copy ADD new_column int DEFAULT 0; }
 step "s2-ddl-drop-column" { ALTER TABLE hash_copy DROP new_column; }
 step "s2-ddl-rename-column" { ALTER TABLE hash_copy RENAME data TO new_column; }
@@ -102,7 +102,7 @@ permutation "s1-initialize" "s1-begin" "s1-copy" "s2-truncate" "s1-commit" "s1-s
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-drop" "s1-commit" "s1-select-count"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-create-index" "s1-commit" "s1-select-count" "s1-show-indexes"
 permutation "s1-initialize" "s1-ddl-create-index" "s1-begin" "s1-copy" "s2-ddl-drop-index" "s1-commit" "s1-select-count" "s1-show-indexes"
-permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-create-index-concurrently" "s1-commit" "s1-select-count" "s1-show-indexes"
+permutation "s1-initialize" "s1-begin" "s1-copy" "s2-flaky-ddl-create-index-concurrently" "s1-commit" "s1-select-count" "s1-show-indexes"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-add-column" "s1-commit" "s1-select-count" "s1-show-columns"
 permutation "s1-initialize" "s1-ddl-add-column" "s1-begin" "s1-copy-additional-column" "s2-ddl-drop-column" "s1-commit" "s1-select-count" "s1-show-columns"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-rename-column" "s1-commit" "s1-select-count" "s1-show-columns"
diff --git a/src/test/regress/spec/isolation_reference_copy_vs_all.spec b/src/test/regress/spec/isolation_reference_copy_vs_all.spec
index b327230d9..e08223db2 100644
--- a/src/test/regress/spec/isolation_reference_copy_vs_all.spec
+++ b/src/test/regress/spec/isolation_reference_copy_vs_all.spec
@@ -68,7 +68,7 @@ step "s2-truncate" { TRUNCATE reference_copy; }
 step "s2-drop" { DROP TABLE reference_copy; }
 step "s2-ddl-create-index" { CREATE INDEX reference_copy_index ON reference_copy(id); }
 step "s2-ddl-drop-index" { DROP INDEX reference_copy_index; }
-step "s2-ddl-create-index-concurrently" { CREATE INDEX CONCURRENTLY reference_copy_index ON reference_copy(id); }
+step "s2-flaky-ddl-create-index-concurrently" { CREATE INDEX CONCURRENTLY flaky_reference_copy_index ON reference_copy(id); }
 step "s2-ddl-add-column" { ALTER TABLE reference_copy ADD new_column int DEFAULT 0; }
 step "s2-ddl-drop-column" { ALTER TABLE reference_copy DROP new_column; }
 step "s2-ddl-rename-column" { ALTER TABLE reference_copy RENAME data TO new_column; }
@@ -91,7 +91,7 @@ permutation "s1-initialize" "s1-begin" "s1-copy" "s2-truncate" "s1-commit" "s1-s
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-drop" "s1-commit" "s1-select-count"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-create-index" "s1-commit" "s1-select-count" "s1-show-indexes"
 permutation "s1-initialize" "s1-ddl-create-index" "s1-begin" "s1-copy" "s2-ddl-drop-index" "s1-commit" "s1-select-count" "s1-show-indexes"
-permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-create-index-concurrently" "s1-commit" "s1-select-count" "s1-show-indexes"
+permutation "s1-initialize" "s1-begin" "s1-copy" "s2-flaky-ddl-create-index-concurrently" "s1-commit" "s1-select-count" "s1-show-indexes"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-add-column" "s1-commit" "s1-select-count" "s1-show-columns"
 permutation "s1-initialize" "s1-ddl-add-column" "s1-begin" "s1-copy-additional-column" "s2-ddl-drop-column" "s1-commit" "s1-select-count" "s1-show-columns"
 permutation "s1-initialize" "s1-begin" "s1-copy" "s2-ddl-rename-column" "s1-commit" "s1-select-count" "s1-show-columns"
diff --git a/src/test/regress/spec/isolation_select_vs_all_on_mx.spec b/src/test/regress/spec/isolation_select_vs_all_on_mx.spec
index 5ce2d0cce..66201af7f 100644
--- a/src/test/regress/spec/isolation_select_vs_all_on_mx.spec
+++ b/src/test/regress/spec/isolation_select_vs_all_on_mx.spec
@@ -99,9 +99,9 @@ step "s2-select-for-update"
 	SELECT run_commands_on_session_level_connection_to_node('SELECT * FROM select_table WHERE id = 6 FOR UPDATE');
 }
 
-step "s2-coordinator-create-index-concurrently"
+step "s2-flaky-coordinator-create-index-concurrently"
 {
-	CREATE INDEX CONCURRENTLY select_table_index ON select_table(id);
+	CREATE INDEX CONCURRENTLY flaky_select_table_index ON select_table(id);
 }
 
 step "s2-commit-worker"
@@ -135,4 +135,4 @@ permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select"
 permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select" "s2-start-session-level-connection" "s2-begin-on-worker" "s2-copy" "s1-commit-worker" "s2-commit-worker" "s1-stop-connection" "s2-stop-connection" "s3-select-count"
 permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select" "s2-begin" "s2-index" "s1-commit-worker" "s2-commit" "s1-stop-connection"
 permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-select" "s2-start-session-level-connection" "s2-begin-on-worker" "s2-select-for-update" "s1-commit-worker" "s2-commit-worker" "s1-stop-connection" "s2-stop-connection"
-permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-disable-binary-protocol-on-worker" "s1-select" "s2-coordinator-create-index-concurrently" "s1-commit-worker" "s1-stop-connection"
+permutation "s1-start-session-level-connection" "s1-begin-on-worker" "s1-disable-binary-protocol-on-worker" "s1-select" "s2-flaky-coordinator-create-index-concurrently" "s1-commit-worker" "s1-stop-connection"