Closed
Description
Basic Infos
- This issue complies with the issue POLICY doc.
- I have read the documentation at readthedocs and the issue is not addressed there.
- I have tested that the issue is present in current master branch (aka latest git).
- I have searched the issue tracker for a similar issue.
- If there is a stack dump, I have decoded it.
- I have filled out all fields below.
Platform
- Hardware: [other (ESP-12 compatible)] (AE-ESP-WROOM-02: see https://akizukidenshi.com/catalog/g/gK-09758/ )]
- Core Version: [a76ef29]
- Development Env: [Arduino IDE (1.8.19)]
- Operating System: [Windows]
Settings in IDE
- Module: [Generic ESP8266 Module]
- Flash Mode: [qio]
- Flash Size: [4MB]
- lwip Variant: [v2 Higher Bandwidth]
- Reset Method: [nodemcu]
- Flash Frequency: [80Mhz]
- CPU Frequency: [160MHz]
- Upload Using: [SERIAL]
- Upload Speed: [512000]
Problem Description
A moderate rate of unexpected HTTP (or socket) disconnections/timeouts is observed when trying to connect to the ESP8266WebServer at a high frequency.
But other HTTP servers belonging to the same WiFi do not see such disconnections/timeouts.
MCVE Sketch
#define WIFI_SSID "YOUR-WIFI-SSID"
#define WIFI_PASSWORD "YOUR-WIFI-PASSWORD"
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
ESP8266WebServer webServer(80);
void setup() {
Serial.begin(74880);
delay(1000);
Serial.print(F("\n\nconnecting to WiFi"));
WiFi.mode(WIFI_STA);
WiFi.begin(F(WIFI_SSID), F(WIFI_PASSWORD));
for (; ; Serial.print('.'), delay(333))
if (WiFi.status() == WL_CONNECTED)
break;
Serial.println(F(", done."));
String addr = WiFi.localIP().toString();
webServer.onNotFound([]() {
webServer.send(404);
});
webServer.on(F("/"), HTTP_GET, []() {
StreamString s;
s.reserve(40);
s.print(F("http://"));
WiFi.localIP().printTo(s);
s.print(F("/index.html"));
webServer.sendHeader(F("Location"), s);
webServer.send(302);
});
Serial.printf_P(PSTR("webServer: http://%s/\n"), addr.c_str());
webServer.on(F("/index.html"), HTTP_GET, []() {
webServer.send(200, F("text/html"), F("<!DOCTYPE html><html>"
"<head><title>WiFi HTTP server</title></head>"
"<body><h1>WiFi HTTP server</h1><p>hello world</p></body>"
"</html>"));
});
Serial.printf_P(PSTR("webServer: http://%s/index.html\n"), addr.c_str());
webServer.on(F("/blob.bin"), HTTP_GET, []() {
size_t length = (ESP.random() & 4095) + 4096;
auto buffer = new uint8_t[length];
ESP.random(buffer, length);
webServer.send(200, PSTR("application/octet-stream"), buffer, length);
delete[] buffer;
});
Serial.printf_P(PSTR("webServer: http://%s/blob.bin\n"), addr.c_str());
webServer.begin();
}
void loop() {
webServer.handleClient();
}Detailed Procedure
- Build the above MVCE and upload it to the chip.
- After the chip reboots and connects to your WiFi, you should get a serial output similar to:
connecting to WiFi................, done.
webServer: http://192.168.2.83/
webServer: http://192.168.2.83/index.html
webServer: http://192.168.2.83/blob.bin
- Now, let's use the HTTP load test program "siege" from a linux PC belonging to the same WiFi network to send high-frequency HTTP requests to the chip. First, write something like this in a text file:
http://192.168.2.83/
http://192.168.2.83/index.html
http://192.168.2.83/blob.bin
- Next, run "siege" in benchmark mode for a some time (a one hour, for example). You'll probably see some alerts in the near future...
vboxuser@Bullseye64:/tmp$ siege -bt 1H -f siege.txt > /dev/null
** SIEGE 4.0.7
** Preparing 25 concurrent users for battle.
The server is now under siege...
[alert] socket: select and discovered it's not ready sock.c:384: Connection timed out
[alert] socket: read check timed out(30) sock.c:273: Connection timed out
[alert] socket: select and discovered it's not ready sock.c:384: Connection timed out
[alert] socket: read check timed out(30) sock.c:273: Connection timed out
...
- Just to be clear, other HTTP servers (Apache, nginx, or even a simple server written in python) don't behave this way. Also, changing the "lwip Variant" setting does the same.
- After an hour the "siege" summary looks roughly like this:
Lifting the server siege...
Transactions: 559940 hits
Availability: 99.81 %
Elapsed time: 3599.58 secs
Data transferred: 855.06 MB
Response time: 0.10 secs
Transaction rate: 155.56 trans/sec
Throughput: 0.24 MB/sec
Concurrency: 15.94
Successful transactions: 560229
Failed transactions: 1088
Longest transaction: 15.92
Shortest transaction: 0.00
Whether or not a failure rate of 0.19% is appropriate is left to the judgment of each person...
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