1 files changed, 64 insertions, 0 deletions
diff --git a/jstests/libs/conn_pool_helpers.js b/jstests/libs/conn_pool_helpers.js
new file mode 100644
index 00000000000..9beb49da1d1
--- /dev/null
+++ b/jstests/libs/conn_pool_helpers.js
@@ -0,0 +1,64 @@
+load("jstests/libs/parallelTester.js");
+
+function configureReplSetFailpoint(st, kDbName, failpoint, modeValue) {
+    st.rs0.nodes.forEach(function(node) {
+        assert.commandWorked(node.getDB("admin").runCommand({
+            configureFailPoint: failpoint,
+            mode: modeValue,
+            data: {
+                shouldCheckForInterrupt: true,
+                nss: kDbName + ".test",
+            },
+        }));
+    });
+}
+
+function launchFinds(mongos, threads, {times, readPref, shouldFail}) {
+    jsTestLog("Starting " + times + " connections");
+    for (var i = 0; i < times; i++) {
+        var thread = new Thread(function(connStr, readPref, dbName, shouldFail) {
+            var client = new Mongo(connStr);
+            const ret = client.getDB(dbName).runCommand(
+                {find: "test", limit: 1, "$readPreference": {mode: readPref}});
+
+            if (shouldFail) {
+                assert.commandFailed(ret);
+            } else {
+                assert.commandWorked(ret);
+            }
+        }, mongos.host, readPref, 'test', shouldFail);
+        thread.start();
+        threads.push(thread);
+    }
+}
+
+function assertHasConnPoolStats(mongos, allHosts, args, checkNum, connPoolStatsCmd = undefined) {
+    checkNum++;
+    jsTestLog("Check #" + checkNum + ": " + tojson(args));
+    let {ready = 0, pending = 0, active = 0, hosts = allHosts, isAbsent, checkStatsFunc} = args;
+    checkStatsFunc = checkStatsFunc ? checkStatsFunc : function(stats) {
+        return stats.available == ready && stats.refreshing == pending &&
+            (stats.inUse + stats.leased) == active;
+    };
+
+    function checkStats(res, host) {
+        let stats = res.hosts[host];
+        if (!stats) {
+            jsTestLog("Connection stats for " + host + " are absent");
+            return isAbsent;
+        }
+
+        jsTestLog("Connection stats for " + host + ": " + tojson(stats));
+        return checkStatsFunc(stats);
+    }
+
+    function checkAllStats() {
+        let cmdName = connPoolStatsCmd ? connPoolStatsCmd : "connPoolStats";
+        let res = mongos.adminCommand({[cmdName]: 1});
+        return hosts.map(host => checkStats(res, host)).every(x => x);
+    }
+
+    assert.soon(checkAllStats, "Check #" + checkNum + " failed", 10000);
+    jsTestLog("Check #" + checkNum + " successful");
+    return checkNum;
+}