From 54f1c682e6fdeefc4cc711258d2f7ab66e59d46c Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 21 Jul 2014 16:26:05 +0200
Subject: [PATCH] Cluster test: unit 04, consistency during resharding.

---
 tests/cluster/tests/04-resharding.tcl | 90 +++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 tests/cluster/tests/04-resharding.tcl

diff --git a/tests/cluster/tests/04-resharding.tcl b/tests/cluster/tests/04-resharding.tcl
new file mode 100644
index 000000000..3264f179d
--- /dev/null
+++ b/tests/cluster/tests/04-resharding.tcl
@@ -0,0 +1,90 @@
+# Failover stress test.
+# In this test a different node is killed in a loop for N
+# iterations. The test checks that certain properties
+# are preseved across iterations.
+
+source "../tests/includes/init-tests.tcl"
+
+test "Create a 5 nodes cluster" {
+    create_cluster 5 5
+}
+
+test "Cluster is up" {
+    assert_cluster_state ok
+}
+
+# Return nno-zero if the specified PID is about a process still in execution,
+# otherwise 0 is returned.
+proc process_is_running {pid} {
+    # PS should return with an error if PID is non existing,
+    # and catch will return non-zero. We want to return non-zero if
+    # the PID exists, so we invert the return value with expr not operator.
+    expr {![catch {exec ps -p $pid}]}
+}
+
+# Our resharding test performs the following actions:
+#
+# - N commands are sent to the cluster in the course of the test.
+# - Every command selects a random key from key:0 to key:MAX-1.
+# - The operation RPUSH key <randomvalue> is perforemd.
+# - Tcl remembers into an array all the values pushed to each list.
+# - After N/2 commands, the resharding process is started in background.
+# - The test continues while the resharding is in progress.
+# - At the end of the test, we wait for the resharding process to stop.
+# - Finally the keys are checked to see if they contain the value they should.
+
+set numkeys 10000
+set numops 200000
+set cluster [redis_cluster 127.0.0.1:[get_instance_attrib redis 0 port]]
+catch {unset content}
+array set content {}
+set tribpid {}
+
+test "Cluster consistency during live resharding" {
+    for {set j 0} {$j < $numops} {incr j} {
+        # Trigger the resharding once we execute half the ops.
+        if {$tribpid ne {} &&
+            ($j % 10000) == 0 &&
+            ![process_is_running $tribpid]} {
+            set tribpid {}
+        }
+
+        if {$j >= $numops/2 && $tribpid eq {}} {
+            puts -nonewline "...Starting resharding..."
+            flush stdout
+            set target [dict get [get_myself [randomInt 5]] id]
+            set tribpid [exec \
+                ../../../src/redis-trib.rb reshard \
+                --from all \
+                --to $target \
+                --slots 100 \
+                --yes \
+                127.0.0.1:[get_instance_attrib redis 0 port] &]
+        }
+
+        # Write random data to random list.
+        set key "key:[randomInt $numkeys]"
+        set ele [randomValue]
+        $cluster rpush $key $ele
+        lappend content($key) $ele
+
+        if {($j % 1000) == 0} {
+            puts -nonewline W; flush stdout
+        }
+    }
+
+    # Wait for the resharding process to end
+    wait_for_condition 1000 500 {
+        [process_is_running $tribpid] == 0
+    } else {
+        fail "Resharding is not terminating after some time."
+    }
+
+}
+
+test "Verify $numkeys keys for consistency with logical content" {
+    # Check that the Redis Cluster content matches our logical content.
+    foreach {key value} [array get content] {
+        assert {[$cluster lrange $key 0 -1] eq $value}
+    }
+}