Thanks to this article (in Simplified Chinese, updated new link), there is a way to embed a TTF that can display Chinese (Traditional and Simplify, and possibly Japanese).
Environment: TCPDF 6.0.020PHP 5.3.8Windows 7
If you follow this post that said: using cid0cs or cid0ct to display Chinese, it can display the character correctly, only to the extend that user installed a correct font package. However, chances are other users who didn't install that package cannot view that PDF since there are several packages and versions of PDF viewer (mainly Adobe). And even worse: even if user installed certain CJK font package, the PDF still not displayed correctly (show empty page).
And according to the official TCPDF documentation about font: The fonts that could be not embedded are only the standard core fonts and CID-0 fonts.
Again, thanks to the post above (in simplified Chinese), now developer can use a font that: Can display ChineseCan be embedded to PDF
The load balancer is done by my colleagues so I am not sure what is the config of it. But one thing to note: Your LB should enable "session stickiness" so that the session will follow visitor. By the way, I am using Round-robins.Session: Actually I did not use session, but it seems that other plugins (like WPML) will use it. If I use Apache load balancer, when I go to wp-admin through load balancing IP, I will not able to login, given the username and password is the same. I will be redirected to login page. So ask your load balancer providers or check your load balancer config and see how to manage the "Session Stickiness" issue.Shared folder: your wp-content/uploads folder must be shared and…