After compiling and installing in the Ubuntu environment, there is a bug in obtaining the maximum number of open files.

[dzhcool]

Note: Before asking a question, please read the FAQ (Please read FAQ before filing an issue) #2716

Description

After compiling and installing ubuntu18.04, an error occurs when starting, indicating that the max open files parameter is incorrect. The log outputs that the system's max open files parameter is inconsistent with the actual setting value.

1. SRS version (Version): 4.0.191

2. SRS log is as follows (Log):

[2021-12-24 13:35:43.250][Error][9308][o342941q][22] invalid max_connections=3000, required=3107, system limit to 1024, total=3007(max_connections=3000, nb_consumed_fds=7). you can change max_connections from 3000 to 1016, or you can login as root and set the limit: ulimit -HSn 3107(Invalid argument)
[2021-12-24 13:35:43.250][Error][9308][o342941q][22] Failed, code=1023 : check config : check connections : 3007 exceed max open files=1024

1. SRS configuration is as follows (Config):

# srs4 example for edge
listen          1935;
pid             /var/run/srs-edge-0.pid;
ff_log_dir      /gpstream/logs/ffmpeg;
srs_log_tank    file;
srs_log_level   trace;
srs_log_file    /gpstream/logs/srs-edge-0.log;
max_connections 3000;
daemon          on;

Replay
Test method:

1. Add debug information at line 206 of trunk/src/main/srs_main_server.cpp.

int main(int argc, char** argv)
{
    int max_open_files = (int)sysconf(_SC_OPEN_MAX);
    printf("[davis-debug] max open files:%d \n", max_open_files);

2. Add debug information at line 2877 of trunk/src/app/srs_app_config.cpp.

srs_error_t SrsConfig::check_number_connections()
{
    int _max_open_files = (int)sysconf(_SC_OPEN_MAX);
    printf("[davis-debug][srs_app_config] max open files:%d \n", _max_open_files);

3. Debug information after compiling and starting.

[davis-debug] max open files:65535 
[2021-12-24 13:35:43.249][Trace][9308][o342941q] XCORE-SRS/4.0.191(Leo)
[2021-12-24 13:35:43.249][Trace][9308][o342941q] config parse complete
[2021-12-24 13:35:43.249][Trace][9308][o342941q] you can check log by: tail -n 30 -f /gpstream/logs/srs-edge-0.log
[2021-12-24 13:35:43.249][Trace][9308][o342941q] please check SRS by: ./etc/init.d/srs status
[davis-debug][srs_app_config] max open files:1024

Expected behavior (Expect)

Expected behavior:

In the Ubuntu system, it is expected that the detection of the "max open files" configuration in trunk/src/app/srs_app_config.cpp should be correct (regardless of whether the system configuration is correct or not, at least the feedback results from the two debugging information in SRS should be consistent).

TRANS_BY_GPT3

[winlinvip]

Does it look okay?

TRANS_BY_GPT3

[winlinvip]

ST_EVENTSYS_DEFAULT is SELECT, of course it is 1024.

This can basically be determined that the underlying system has not been modified, fd limitation is a very basic Linux feature, please double-check.

TRANS_BY_GPT3

[winlinvip]

👍 Not bad, not bad. Found the reason, really not easy.

For the solution, it is better to proactively define this macro MD_HAVE_EPOLL. ST provides a method to set EXTRA_FLAGS, you can search for the variable _ST_EXTRA_CFLAGS.

TRANS_BY_GPT3

[winlinvip]

I have updated it, please test version 4.0.213. Remember to delete the 'objs' folder and reconfigure.

TRANS_BY_GPT3