diff --git a/utils/zookeeper-dump-tree/main.cpp b/utils/zookeeper-dump-tree/main.cpp
index 4614ee577e7..b50d6e97235 100644
--- a/utils/zookeeper-dump-tree/main.cpp
+++ b/utils/zookeeper-dump-tree/main.cpp
@@ -7,81 +7,94 @@
 
 
 int main(int argc, char ** argv)
-try
 {
-    boost::program_options::options_description desc("Allowed options");
-    desc.add_options()
-        ("help,h", "produce help message")
-        ("address,a", boost::program_options::value<std::string>()->required(),
-            "addresses of ZooKeeper instances, comma separated. Example: example01e.yandex.ru:2181")
-        ("path,p", boost::program_options::value<std::string>()->default_value("/"),
-            "where to start")
-    ;
-
-    boost::program_options::variables_map options;
-    boost::program_options::store(boost::program_options::parse_command_line(argc, argv, desc), options);
-
-    if (options.count("help"))
+    try
     {
-        std::cout << "Dump paths of all nodes in ZooKeeper." << std::endl;
-        std::cout << "Usage: " << argv[0] << " [options]" << std::endl;
-        std::cout << desc << std::endl;
+        boost::program_options::options_description desc("Allowed options");
+        desc.add_options()
+            ("help,h", "produce help message")
+            ("address,a", boost::program_options::value<std::string>()->required(),
+                "addresses of ZooKeeper instances, comma separated. Example: example01e.yandex.ru:2181")
+            ("path,p", boost::program_options::value<std::string>()->default_value("/"),
+                "where to start")
+        ;
+
+        boost::program_options::variables_map options;
+        boost::program_options::store(boost::program_options::parse_command_line(argc, argv, desc), options);
+
+        if (options.count("help"))
+        {
+            std::cout << "Dump paths of all nodes in ZooKeeper." << std::endl;
+            std::cout << "Usage: " << argv[0] << " [options]" << std::endl;
+            std::cout << desc << std::endl;
+            return 1;
+        }
+
+        zkutil::ZooKeeperPtr zookeeper = std::make_shared<zkutil::ZooKeeper>(options.at("address").as<std::string>());
+
+        std::string initial_path = options.at("path").as<std::string>();
+
+        std::list<std::pair<std::string, std::future<Coordination::ListResponse>>> list_futures;
+        list_futures.emplace_back(initial_path, zookeeper->asyncGetChildren(initial_path));
+
+        size_t num_reconnects = 0;
+        constexpr size_t max_reconnects = 100;
+
+        auto ensureSession = [&]
+        {
+            if (zookeeper->expired())
+            {
+                if (num_reconnects == max_reconnects)
+                    return false;
+                ++num_reconnects;
+                std::cerr << "num_reconnects: " << num_reconnects << "\n";
+                zookeeper = zookeeper->startNewSession();
+            }
+            return true;
+        };
+
+        for (auto it = list_futures.begin(); it != list_futures.end(); ++it)
+        {
+            Coordination::ListResponse response;
+
+            try
+            {
+                response = it->second.get();
+            }
+            catch (const Coordination::Exception & e)
+            {
+                if (e.code == Coordination::Error::ZNONODE)
+                {
+                    continue;
+                }
+                else if (Coordination::isHardwareError(e.code))
+                {
+                    /// Reinitialize the session and move the node to the end of the queue for later retry.
+                    if (!ensureSession())
+                        throw;
+                    list_futures.emplace_back(it->first, zookeeper->asyncGetChildren(it->first));
+                    continue;
+                }
+                else
+                    throw;
+            }
+
+            std::cout << it->first << '\t' << response.stat.numChildren << '\t' << response.stat.dataLength << '\n';
+
+            for (const auto & name : response.names)
+            {
+                std::string child_path = it->first == "/" ? it->first + name : it->first + '/' + name;
+
+                ensureSession();
+                list_futures.emplace_back(child_path, zookeeper->asyncGetChildren(child_path));
+            }
+        }
+
+        return 0;
+    }
+    catch (...)
+    {
+        std::cerr << DB::getCurrentExceptionMessage(true) << '\n';
         return 1;
     }
-
-    zkutil::ZooKeeperPtr zookeeper = std::make_shared<zkutil::ZooKeeper>(options.at("address").as<std::string>());
-
-    std::string initial_path = options.at("path").as<std::string>();
-
-    std::list<std::pair<std::string, std::future<Coordination::ListResponse>>> list_futures;
-    list_futures.emplace_back(initial_path, zookeeper->asyncGetChildren(initial_path));
-
-    size_t num_reconnects = 0;
-    constexpr size_t max_reconnects = 100;
-
-    for (auto it = list_futures.begin(); it != list_futures.end(); ++it)
-    {
-        Coordination::ListResponse response;
-
-        try
-        {
-            response = it->second.get();
-        }
-        catch (const Coordination::Exception & e)
-        {
-            if (e.code == Coordination::Error::ZNONODE)
-            {
-                continue;
-            }
-            else if (Coordination::isHardwareError(e.code))
-            {
-                /// Reinitialize the session and move the node to the end of the queue for later retry.
-                if (zookeeper->expired())
-                {
-                    if (num_reconnects == max_reconnects)
-                        throw;
-                    ++num_reconnects;
-                    zookeeper = zookeeper->startNewSession();
-                }
-
-                list_futures.emplace_back(it->first, zookeeper->asyncGetChildren(it->first));
-                continue;
-            }
-            else
-                throw;
-        }
-
-        std::cout << it->first << '\t' << response.stat.numChildren << '\t' << response.stat.dataLength << '\n';
-
-        for (const auto & name : response.names)
-        {
-            std::string child_path = it->first == "/" ? it->first + name : it->first + '/' + name;
-            list_futures.emplace_back(child_path, zookeeper->asyncGetChildren(child_path));
-        }
-    }
-}
-catch (...)
-{
-    std::cerr << DB::getCurrentExceptionMessage(true) << '\n';
-    throw;
 }