client.publish() takes 200ms to execute

[mccarr]

Hi,
I'm trying to publish at 10Hz or greater but it seems like the library can't handle more than about 4 hz. By putting print statements just before publish(), it looks like this function call takes ~220ms. Is this right? Seems like a very long time for a protocol that is designed to be lightweight and speedy.

I tested the time for publish() to execute with both a long payload and a single character payload with basically no difference.

I'm connecting to AWS using TLS with the CA cert, client cert and client key.

Is this a fundamental limit on the speed of MQTT or am I doing something wrong with settings or configuration?

[hirotakaster]

Hi @mccarr ,
I update this library to 0.2.17 now. Please use latest version.

And now I test on my AWS IoT works well(10hz) with Photon firmware version 0.8.0(rc-9).

#include "MQTT-TLS.h"

void callback(char* topic, byte* payload, unsigned int length);

#define AMAZON_IOT_ROOT_CA_PEM                                          \
"-----BEGIN CERTIFICATE----- \r\n"                                      \
"MIIE0zCCA7ugAwIBAgIQGNrRniZ96LtKIVjNzGs7SjANBgkqhkiG9w0BAQUFADCB\r\n"  \
"yjELMAkGA1UEBhMCVVMxFzAVBgNVBAoTDlZlcmlTaWduLCBJbmMuMR8wHQYDVQQL\r\n"  \
"ExZWZXJpU2lnbiBUcnVzdCBOZXR3b3JrMTowOAYDVQQLEzEoYykgMjAwNiBWZXJp\r\n"  \
"U2lnbiwgSW5jLiAtIEZvciBhdXRob3JpemVkIHVzZSBvbmx5MUUwQwYDVQQDEzxW\r\n"  \
"ZXJpU2lnbiBDbGFzcyAzIFB1YmxpYyBQcmltYXJ5IENlcnRpZmljYXRpb24gQXV0\r\n"  \
"aG9yaXR5IC0gRzUwHhcNMDYxMTA4MDAwMDAwWhcNMzYwNzE2MjM1OTU5WjCByjEL\r\n"  \
"MAkGA1UEBhMCVVMxFzAVBgNVBAoTDlZlcmlTaWduLCBJbmMuMR8wHQYDVQQLExZW\r\n"  \
"ZXJpU2lnbiBUcnVzdCBOZXR3b3JrMTowOAYDVQQLEzEoYykgMjAwNiBWZXJpU2ln\r\n"  \
"biwgSW5jLiAtIEZvciBhdXRob3JpemVkIHVzZSBvbmx5MUUwQwYDVQQDEzxWZXJp\r\n"  \
"U2lnbiBDbGFzcyAzIFB1YmxpYyBQcmltYXJ5IENlcnRpZmljYXRpb24gQXV0aG9y\r\n"  \
"aXR5IC0gRzUwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCvJAgIKXo1\r\n"  \
"nmAMqudLO07cfLw8RRy7K+D+KQL5VwijZIUVJ/XxrcgxiV0i6CqqpkKzj/i5Vbex\r\n"  \
"t0uz/o9+B1fs70PbZmIVYc9gDaTY3vjgw2IIPVQT60nKWVSFJuUrjxuf6/WhkcIz\r\n"  \
"SdhDY2pSS9KP6HBRTdGJaXvHcPaz3BJ023tdS1bTlr8Vd6Gw9KIl8q8ckmcY5fQG\r\n"  \
"BO+QueQA5N06tRn/Arr0PO7gi+s3i+z016zy9vA9r911kTMZHRxAy3QkGSGT2RT+\r\n"  \
"rCpSx4/VBEnkjWNHiDxpg8v+R70rfk/Fla4OndTRQ8Bnc+MUCH7lP59zuDMKz10/\r\n"  \
"NIeWiu5T6CUVAgMBAAGjgbIwga8wDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8E\r\n"  \
"BAMCAQYwbQYIKwYBBQUHAQwEYTBfoV2gWzBZMFcwVRYJaW1hZ2UvZ2lmMCEwHzAH\r\n"  \
"BgUrDgMCGgQUj+XTGoasjY5rw8+AatRIGCx7GS4wJRYjaHR0cDovL2xvZ28udmVy\r\n"  \
"aXNpZ24uY29tL3ZzbG9nby5naWYwHQYDVR0OBBYEFH/TZafC3ey78DAJ80M5+gKv\r\n"  \
"MzEzMA0GCSqGSIb3DQEBBQUAA4IBAQCTJEowX2LP2BqYLz3q3JktvXf2pXkiOOzE\r\n"  \
"p6B4Eq1iDkVwZMXnl2YtmAl+X6/WzChl8gGqCBpH3vn5fJJaCGkgDdk+bW48DW7Y\r\n"  \
"5gaRQBi5+MHt39tBquCWIMnNZBU4gcmU7qKEKQsTb47bDN0lAtukixlE0kF6BWlK\r\n"  \
"WE9gyn6CagsCqiUXObXbf+eEZSqVir2G3l6BFoMtEMze/aiCKm0oHw0LxOXnGiYZ\r\n"  \
"4fQRbxC1lfznQgUy286dUV4otp6F01vvpX1FQHKOtw5rDgb7MzVIcbidJ4vEZV8N\r\n"  \
"hnacRHr2lVz2XTIIM6RUthg/aFzyQkqFOFSDX9HoLPKsEdao7WNq\r\n"  \
"-----END CERTIFICATE----- "
const char amazonIoTRootCaPem[] = AMAZON_IOT_ROOT_CA_PEM;

#define CELINT_KEY_CRT_PEM                                              \
"-----BEGIN CERTIFICATE----- \r\n"                                      \
"-----END CERTIFICATE----- "
const char clientKeyCrtPem[] = CELINT_KEY_CRT_PEM;

#define CELINT_KEY_PEM                                                  \
"-----BEGIN RSA PRIVATE KEY-----\r\n"                                   \
"-----END RSA PRIVATE KEY----- "
const char clientKeyPem[] = CELINT_KEY_PEM;

MQTT client("XXXXX.iot.us-east-1.amazonaws.com", 8883, callback);

// recieve message
void callback(char* topic, byte* payload, unsigned int length) {
    char p[length + 1];
    memcpy(p, payload, length);
    p[length] = NULL;
    String message(p);

    if (message.equals("RED"))
        RGB.color(255, 0, 0);
    else if (message.equals("GREEN"))
        RGB.color(0, 255, 0);
    else if (message.equals("BLUE"))
        RGB.color(0, 0, 255);
    else
        RGB.color(255, 255, 255);
    delay(1000);
}

#define ONE_DAY_MILLIS (24 * 60 * 60 * 1000)
unsigned long lastSync = millis();
int counter = 0;
void setup() {
    if (millis() - lastSync > ONE_DAY_MILLIS) {
        Particle.syncTime();
        lastSync = millis();
    }

    RGB.control(true);

    // enable tls. set Root CA pem, private key file.
    client.enableTls(amazonIoTRootCaPem, sizeof(amazonIoTRootCaPem),
                     clientKeyCrtPem, sizeof(clientKeyCrtPem),
                     clientKeyPem, sizeof(clientKeyPem));
    Serial.println("tls enable");

    // connect to the server
    client.connect("sparkclient");

    // publish/subscribe
    if (client.isConnected()) {
        Serial.println("client connected");
        client.publish("outTopic/message", "hello world");
        client.subscribe("inTopic/message");
    }
}

void loop() {
    if (client.isConnected()) {
        client.loop();
    }
    client.publish("outTopic/message", "hello");
    Serial.println(counter++);
    delay(100);
}