Question about ssl_asynch on

[Edelweiss014]

Hi there,

When I was trying QAT SW (with async_mode_nginx v0.5.0), I found out that if I switched on ssl_asynch, it automatically switched ssl on. Is there any specific reason for this?
I also noticed that you removed this part of codes in v0.5.2:

/* If ssl_asynch on is configured, then ssl on is configured by default
 * This will align 'ssl_asynch on;' and 'listen port ssl' diretives
 * */
pssl = (ngx_flag_t *) ((char *)conf + offsetof(ngx_http_ssl_srv_conf_t, enable));
pssl_asynch = (ngx_flag_t *) ((char *)conf + cmd->offset);

if(*pssl_asynch && *pssl != 1) {
    *pssl = *pssl_asynch;
}

Does this mean that I can now use my v0.5.0 and remove this logic without any other side effects?

Thank you very much.

[hardikpatel9]

Hi @Edelweiss014 ,

Yes,  NGINX deprecated the legacy directive ssl on; and removed it in version 1.25.1, and the latest NGINX requires using the listen 443 ssl; You can remove that logic from v0.5.0. Given your current situation with strict project timelines preventing a full upgrade, removing just this specific code block is a minimal-risk change that will resolve your immediate issue but need to test for other aspects.
I suggest considering an upgrade to the latest async NGINX v1.0.0 when your project timeline permits. The v1.0.0 release incorporates numerous improvements, bug fixes, and optimizations beyond just this particular issue, and it aligns better with latest NGINX conventions and best practices.

Please let me know if you need further clarification or assistance!

[Edelweiss014]

Hi Hardikkumar,

Thank you very much with this information! Looks like we can just remove the logic.
Actually, I do have another question about ssl_asynch: what is the difference between "ssl_asynch on" and the "asynch" directive in "listen 443 ssl asynch"? I noticed that you only included "ssl_asynch" in README file but "asynch" in listen directives also worked in most situations.
I thought these two were the same, but our program crashed when using the latter (the one in "listen" directives).
Could you please explain a little bit to me about the difference?
Thank you very much for your time.