add load balancer metrics

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:latest as build
+FROM alpine:latest AS build
 
 RUN apk update
 RUN apk add --no-cache zig
@@ -9,7 +9,7 @@ COPY ./build.zig .
 
 RUN zig build --release=fast
 
-FROM alpine:latest as app
+FROM alpine:latest AS app
 WORKDIR /app
 COPY --from=build /app/zig-out/bin/zigpay .
 

docker-compose.yml

@@ -19,7 +19,7 @@ services:
     deploy:
       resources:
         limits:
-          cpus: "0.30"
+          cpus: "0.20"
           memory: "50MB"
   zig1: &zig
     container_name: zig-pay-1
@@ -40,7 +40,7 @@ services:
     deploy:
       resources:
         limits:
-          cpus: "0.60"
+          cpus: "0.20"
           memory: "50MB"
   zig2: 
     <<: *zig

src/endpoints/payments.zig

@@ -95,7 +95,6 @@ const template_json_summary: []const u8 =
 ;
 
 fn getSummary(req: *Request, res: *Response) void {
-    std.Thread.sleep(1_000_000 * 10);
     var from: ?DateTime = null;
     var to: ?DateTime = null;
 

src/load_balancer.zig

@@ -13,6 +13,10 @@ const Stream = net.Stream;
 
 const BUFFER_SIZE = 1024;
 
+var metrics_mutex = std.Thread.Mutex{};
+var metrics_num_requests: u64 = 0;
+var metrics_sum_req_time: u64 = 0;
+
 const UpstreamConnectionState = enum { inactive, available, occupied };
 
 const UpstreamConnection = struct {
@@ -147,6 +151,8 @@ pub const LoadBalancer = struct {
 
         buffer_request[0] = 0;
 
+        var timer = std.time.Timer.start() catch return;
+
         while (true) {
             var req_len: usize = 1;
 
@@ -168,6 +174,7 @@ pub const LoadBalancer = struct {
                     break;
                 }
             }
+            timer.reset();
 
             upstream.stream.writeAll(buffer_request[0..req_len]) catch |err| {
                 log.err("Error when writing to upstream {}\n", .{err});
@@ -187,6 +194,18 @@ pub const LoadBalancer = struct {
                 log.err("Error when write from connection {}\n", .{err});
                 return;
             };
+
+            const req_time_ns = timer.lap();
+
+            metrics_mutex.lock();
+            metrics_num_requests += 1;
+            metrics_sum_req_time += req_time_ns;
+
+            if (metrics_num_requests % 5000 == 0) {
+                std.debug.print("average requests time ns: {d}\n", .{metrics_sum_req_time / metrics_num_requests});
+            }
+
+            metrics_mutex.unlock();
         }
     }
 };

src/payment_integrator.zig

@@ -53,7 +53,7 @@ pub const PaymentIntegrator = struct {
 
     fn startProcess(self: *PaymentIntegrator) void {
         while (true) {
-            Thread.sleep(10_000_000);
+            Thread.sleep(50_000_000);
 
             self.verifyTailSize();
             self.processPayments();
@@ -112,8 +112,8 @@ pub const PaymentIntegrator = struct {
     }
 
     pub fn newPaymentEvent(payment: *payments.Payment) void {
-        payment_integrator.mutex.lock();
+        //payment_integrator.mutex.lock();
-        defer payment_integrator.mutex.unlock();
+        //defer payment_integrator.mutex.unlock();
 
         const head = payment_integrator.head % MAX_QUEUE_SIZE;
         payment_integrator.queue[head].payment = payment;

src/services/http_service.zig

@@ -194,7 +194,7 @@ pub const HttpService = struct {
 
     pub fn startMessenger(self: *HttpService, connections: []ServiceConnection, tickets: []ServiceTicket, thread_id: usize) void {
         while (true) {
-            Thread.sleep(20_000_000);
+            Thread.sleep(30_000_000);
             if (self.thread_stop[thread_id]) {
                 var conn_open = false;