As described in the title, NGINX gives me an upstream sent to big header error in the error logs.
2017/09/20 13:30:10 [error] 23665#23665: *100918355 upstream sent too big header while reading response header from upstream, client: xxx.xxx.xxx.xxx, server: staging.xxx.xxx.com, request: "POST /media_plans HTTP/1.1", upstream: "http://xxx.xxx.xxx.xxx:xxxx/media_plans", host: "xxx.xxx.com", referrer: "https://xxx.xxx.com/advertisers/4/dealers"
I found a few other posts and blogs telling me to increase the buffer size like this,
fastcgi_buffers 16 16k;
fastcgi_buffer_size 32k;
Now i do not mind changing the config of nginx it seems that it doesn't solve the issue and i actually want to know what is causing it instead of just increasing buffer sizes.
If i am understanding it correct the command below shows me the average size of the headers and the maximum size of them.
awk '($9 ~ /200/) { i++;sum+=$10;max=$10>max?$10:max; } END { printf("Maximum: %d\nAverage: %d\n",max,i?sum/i:0); }' access.log
Maximum: 1236947
Average: 1529
A maximum of 1.23 mb has starting me to wonder that maybe something else is wrong. I'd rather fix the origin of the issue than to increase buffer sizes.
How can i find out what the size of the headers is within rails?