Ignore resize threshold on idle qbuf resizing (#9322)

Also update qbuf tests to verify both idle and peak based resizing logic.
And delete unused function: getClientsMaxBuffers

1 files changed, 31 insertions, 13 deletions

diff --git a/tests/unit/querybuf.tcl b/tests/unit/querybuf.tcl
index 458f8e844..bbbea12f4 100644
--- a/tests/unit/querybuf.tcl
+++ b/tests/unit/querybuf.tcl
@@ -21,28 +21,46 @@ start_server {tags {"querybuf slow"}} {
     # The test will run at least 2s to check if client query
     # buffer will be resized when client idle 2s.
     test "query buffer resized correctly" {
-        # Memory will increase by more than 32k due to client query buffer.
-        set rd [redis_deferring_client]
+        set rd [redis_client]
         $rd client setname test_client
         set orig_test_client_qbuf [client_query_buffer test_client]
+        # Make sure query buff has less than the peak resize threshold (PROTO_RESIZE_THRESHOLD) 32k
+        # but at least the basic IO reading buffer size (PROTO_IOBUF_LEN) 16k
         assert {$orig_test_client_qbuf >= 16384 && $orig_test_client_qbuf < 32768}
 
-        # Check that the initial query buffer is not resized if it is idle for more than 2s
+        # Check that the initial query buffer is resized after 2 sec
         wait_for_condition 1000 10 {
-            [client_idle_sec test_client] > 3 && [client_query_buffer test_client] == $orig_test_client_qbuf
+            [client_idle_sec test_client] >= 3 && [client_query_buffer test_client] == 0
         } else {
-            fail "query buffer was resized"
+            fail "query buffer was not resized"
         }
+        $rd close
+    }
 
-        # Fill query buffer to more than 32k
-        $rd set bigstring v ;# create bigstring in advance to avoid adding extra memory
-        $rd set bigstring [string repeat A 32768] nx
+    test "query buffer resized correctly when not idle" {
+        # Memory will increase by more than 32k due to client query buffer.
+        set rd [redis_client]
+        $rd client setname test_client
 
-        # Wait for query buffer to be resized to 0.
-        wait_for_condition 1000 10 {
-            [client_query_buffer test_client] == 0
-        } else {
-            fail "querybuf expected to be resized"
+        # Create a large query buffer (more than PROTO_RESIZE_THRESHOLD - 32k)
+        $rd set x [string repeat A 400000]
+
+        # Make sure query buff is larger than the peak resize threshold (PROTO_RESIZE_THRESHOLD) 32k
+        set orig_test_client_qbuf [client_query_buffer test_client]
+        assert {$orig_test_client_qbuf > 32768}
+
+        # Wait for qbuf to shrink due to lower peak
+        set t [clock milliseconds]
+        while true {
+            # Write something smaller, so query buf peak can shrink
+            $rd set x [string repeat A 100]
+            set new_test_client_qbuf [client_query_buffer test_client]
+            if {$new_test_client_qbuf < $orig_test_client_qbuf} { break } 
+            if {[expr [clock milliseconds] - $t] > 1000} { break }
+            after 10
         }
+        # Validate qbuf shrunk but isn't 0 since we maintain room based on latest peak
+        assert {[client_query_buffer test_client] > 0 && [client_query_buffer test_client] < $orig_test_client_qbuf}
+        $rd close
     }
 }