Nginx: could not build map_hash, you should increase map_hash_bucket_size: 64

Question

I need to use redirect map with quite a lot rules (2k+ lines, file size is ~200K)

I have the following settings in nginx:

map $uri $new_uri {
        include /etc/nginx/conf.d/redirects.map;
}

server {
        listen 80 default_server;
        listen [::]:80 default_server;

        # redirects
        if ($new_uri) {
                rewrite ^ $new_uri permanent;
        }

as described here and found here. The problem : configtest fails:

nginx: [emerg] could not build map_hash, you should increase map_hash_bucket_size: 64

I tried to increase map_hash_max_size and map_hash_bucket_size to quite crazy values:

map $uri $new_uri {
        map_hash_max_size 262144;
        map_hash_bucket_size 262144;
        include /etc/nginx/conf.d/redirects.map;
}

but still have the same error (ending exactly with '64'). I selected those values so they are bigger than the file size. I made sure I'm editing live config by adding "blabla" and see 'unknown directive'

So, how those values should be set? There's not much details in the official doc, unfortunately.

Solution 1

map_hash_max_size and map_hash_bucket_size must be in http context, i.e. outside of map directive.

map_hash_max_size 262144;
map_hash_bucket_size 262144;
map $uri $new_uri {
    include /etc/nginx/conf.d/redirects.map;
}

Solution 2

I put it on the top of the http {} and it worked. Don't put it outside http {}

Comments

[Michael Hampton]

How does your answer differ from the existing answer?

[Michael Hampton]

Well, having it twice in your config causes that problem.

[tread]

Yip. Another reason why it is better to put this setting in the main nginx config.

[Kevin Nguyen]

I set up right above the map but still got the same error. It's really weird.

[Alexey Ten]

@KevinNguyen what error?

[Kevin Nguyen]

Nginx: could not build map_hash, you should increase map_hash_bucket_size: 64. I posted my answer btw.

[Michael Hampton]

It is not obvious but it also needs to appear before the map directives.

[black sensei]

@AlexeyTen this solution works well in with nginx 1.16 but not with nginx 1.18.