Compression

HTTP compression allows you to shrink the body of a response before it’s relayed to a client which results in using less network bandwidth per request. From a client’s perspective, this reduces latency.

Enable compression for responses Jump to heading #

1. In a frontend, backend, listen or defaults section, add the filter compression and compression algo directives. Set compression algo to one of the following:

   • deflate
   • gzip
   • identity
   • raw-deflate

   haproxy
   backend web_servers
     filter compression
     compression algo gzip

   haproxy
   backend web_servers
     filter compression
     compression algo gzip

   Responses will be compressed only if they are not already compressed.

2. Add a compression type directive, which specifies the MIME types to compress:

   haproxy
   backend web_servers
     filter compression
     compression algo gzip
     compression type text/css text/html text/javascript application/javascript text/plain text/xml application/json

   haproxy
   backend web_servers
     filter compression
     compression algo gzip
     compression type text/css text/html text/javascript application/javascript text/plain text/xml application/json

3. Optional: Add a compression offload directive, which states that the load balancer will remove the Accept-Encoding header before forwarding a request to backend servers, which prevents the servers from performing compression, offloading that work to the load balancer. The compression offload directive may only be placed in frontend, listen, and backend sections:

   haproxy
   backend web_servers
     filter compression
     compression algo gzip
     compression type text/css text/html text/javascript application/javascript text/plain text/xml application/json
     compression offload

   haproxy
   backend web_servers
     filter compression
     compression algo gzip
     compression type text/css text/html text/javascript application/javascript text/plain text/xml application/json
     compression offload

Enable compression for requests Jump to heading #

You can also shrink the body of a request before it’s relayed to a backend server.

1. In a frontend, backend, listen or defaults section, add the filter compression and compression direction directives. Set the compression direction to one of:

   • request to compress only requests
   • response to compress only responses
   • both to compress both requests and responses

   haproxy
   backend web_servers
     filter compression
     compression direction both

   haproxy
   backend web_servers
     filter compression
     compression direction both

2. Specify the compression algorithm:

   • If you set compression direction to request or both, add an algo-req directive.
   • If you set compression direction to response or both, add an algo-res directive.

   Set the compression algorithm to one of the following:

   • deflate
   • gzip
   • identity
   • raw-deflate.

   You can choose different compression algorithms for responses and requests.

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate 
     compression algo-res gzip

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate 
     compression algo-res gzip

   Responses and requests will be compressed only if they are not already compressed:

3. Specify the MIME types to compress for requests and / or responses depending on which compression direction you specified:

   • If you set compression direction to request or both, add a compression type-req directive.
   • If you set the compression direction to response or both, add a compression type-res directive.

   You can specify different MIME types for requests and responses.

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate
     compression type-req application/json text/xml text/plain
     compression algo-res gzip
     compression type-res text/css text/html text/plain text/xml text/javascript application/javascript application/json

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate
     compression type-req application/json text/xml text/plain
     compression algo-res gzip
     compression type-res text/css text/html text/plain text/xml text/javascript application/javascript application/json

4. Optional: Add a compression offload directive, which states that the load balancer will remove the Accept-Encoding header before forwarding a request to backend servers, which prevents the servers from performing compression, offloading that work to the load balancer. The compression offload directive may only be placed in frontend, listen, and backend sections:

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate
     compression type-req application/json text/xml text/plain 
     compression algo-res gzip
     compression type-res text/css text/html text/plain text/xml text/javascript application/javascript application/json
     compression offload

   haproxy
   backend web_servers
     filter compression
     compression direction both 
     compression algo-req deflate
     compression type-req application/json text/xml text/plain 
     compression algo-res gzip
     compression type-res text/css text/html text/plain text/xml text/javascript application/javascript application/json
     compression offload

Process-level settings Jump to heading #

Add any of the following directives to the global section to customize compression:

See also Jump to heading #

• Compression reference
• maxcompcpuusage
• maxcomprate
• tune.comp.maxlevel