Packet flow between Client - Load balancer - Server
I am building my own load balancer in C++. But I lack some fundamental knowledge of how requests/responses flow in such routing configuration.
Suppose I have application at www.application.com
and that DNS returns ip-address of Load balancer when requested. Client's ip is client_ip
, balancer's one is balancer_ip
and server's - server_ip
. So here is sequence of packets generated in a network:
1) The first packet is generated by client requesting load balancer:
+-----------+-------------+---------+
| Source | Destination | Request |
+-----------+-------------+---------+
| client_ip | balancer_ip | /hello |
+-----------+-------------+---------+
2) The second one is generated by balancer making request to server and putting client_ip
into X-Forwarded-For
header:
+-------------+-------------+---------+-----------------+
| Source | Destination | Request | X-Forwarded-For |
+-------------+-------------+---------+-----------------+
| balancer_ip | server_ip | /hello | client_ip |
+-------------+-------------+---------+-----------------+
3) The server is receives request and makes response back to load balancer. X-Forwarded-For
remains the same.
+-----------+-------------+------------------+-----------------+
| Source | Destination | Response | X-Forwarded-For |
+-----------+-------------+------------------+-----------------+
| server_ip | balancer_ip | response_message | client_ip |
+-----------+-------------+------------------+-----------------+
4) Balancer receives response from server and creates its own response back to client, by taking client's ip-address from X-Forwarded-For
header and putting it into destination:
+-------------+-------------+------------------+
| Source | Destination | Response |
+-------------+-------------+------------------+
| balancer_ip | client_ip | response_message |
+-------------+-------------+------------------+
Suppose all communcation is performed in HTTP. Is this a correct way of performing redirects between client - load balancer - server? I have looked through standard request/response fields and X-Forwarded-For
wasn't in the list of standard and non-standard responses. Also if this is the correct way, won't such popular frameworks such as Spring, Django, Node.js discard X-Forwarded-For
header?
networking ip routing load-balancer
add a comment |
I am building my own load balancer in C++. But I lack some fundamental knowledge of how requests/responses flow in such routing configuration.
Suppose I have application at www.application.com
and that DNS returns ip-address of Load balancer when requested. Client's ip is client_ip
, balancer's one is balancer_ip
and server's - server_ip
. So here is sequence of packets generated in a network:
1) The first packet is generated by client requesting load balancer:
+-----------+-------------+---------+
| Source | Destination | Request |
+-----------+-------------+---------+
| client_ip | balancer_ip | /hello |
+-----------+-------------+---------+
2) The second one is generated by balancer making request to server and putting client_ip
into X-Forwarded-For
header:
+-------------+-------------+---------+-----------------+
| Source | Destination | Request | X-Forwarded-For |
+-------------+-------------+---------+-----------------+
| balancer_ip | server_ip | /hello | client_ip |
+-------------+-------------+---------+-----------------+
3) The server is receives request and makes response back to load balancer. X-Forwarded-For
remains the same.
+-----------+-------------+------------------+-----------------+
| Source | Destination | Response | X-Forwarded-For |
+-----------+-------------+------------------+-----------------+
| server_ip | balancer_ip | response_message | client_ip |
+-----------+-------------+------------------+-----------------+
4) Balancer receives response from server and creates its own response back to client, by taking client's ip-address from X-Forwarded-For
header and putting it into destination:
+-------------+-------------+------------------+
| Source | Destination | Response |
+-------------+-------------+------------------+
| balancer_ip | client_ip | response_message |
+-------------+-------------+------------------+
Suppose all communcation is performed in HTTP. Is this a correct way of performing redirects between client - load balancer - server? I have looked through standard request/response fields and X-Forwarded-For
wasn't in the list of standard and non-standard responses. Also if this is the correct way, won't such popular frameworks such as Spring, Django, Node.js discard X-Forwarded-For
header?
networking ip routing load-balancer
add a comment |
I am building my own load balancer in C++. But I lack some fundamental knowledge of how requests/responses flow in such routing configuration.
Suppose I have application at www.application.com
and that DNS returns ip-address of Load balancer when requested. Client's ip is client_ip
, balancer's one is balancer_ip
and server's - server_ip
. So here is sequence of packets generated in a network:
1) The first packet is generated by client requesting load balancer:
+-----------+-------------+---------+
| Source | Destination | Request |
+-----------+-------------+---------+
| client_ip | balancer_ip | /hello |
+-----------+-------------+---------+
2) The second one is generated by balancer making request to server and putting client_ip
into X-Forwarded-For
header:
+-------------+-------------+---------+-----------------+
| Source | Destination | Request | X-Forwarded-For |
+-------------+-------------+---------+-----------------+
| balancer_ip | server_ip | /hello | client_ip |
+-------------+-------------+---------+-----------------+
3) The server is receives request and makes response back to load balancer. X-Forwarded-For
remains the same.
+-----------+-------------+------------------+-----------------+
| Source | Destination | Response | X-Forwarded-For |
+-----------+-------------+------------------+-----------------+
| server_ip | balancer_ip | response_message | client_ip |
+-----------+-------------+------------------+-----------------+
4) Balancer receives response from server and creates its own response back to client, by taking client's ip-address from X-Forwarded-For
header and putting it into destination:
+-------------+-------------+------------------+
| Source | Destination | Response |
+-------------+-------------+------------------+
| balancer_ip | client_ip | response_message |
+-------------+-------------+------------------+
Suppose all communcation is performed in HTTP. Is this a correct way of performing redirects between client - load balancer - server? I have looked through standard request/response fields and X-Forwarded-For
wasn't in the list of standard and non-standard responses. Also if this is the correct way, won't such popular frameworks such as Spring, Django, Node.js discard X-Forwarded-For
header?
networking ip routing load-balancer
I am building my own load balancer in C++. But I lack some fundamental knowledge of how requests/responses flow in such routing configuration.
Suppose I have application at www.application.com
and that DNS returns ip-address of Load balancer when requested. Client's ip is client_ip
, balancer's one is balancer_ip
and server's - server_ip
. So here is sequence of packets generated in a network:
1) The first packet is generated by client requesting load balancer:
+-----------+-------------+---------+
| Source | Destination | Request |
+-----------+-------------+---------+
| client_ip | balancer_ip | /hello |
+-----------+-------------+---------+
2) The second one is generated by balancer making request to server and putting client_ip
into X-Forwarded-For
header:
+-------------+-------------+---------+-----------------+
| Source | Destination | Request | X-Forwarded-For |
+-------------+-------------+---------+-----------------+
| balancer_ip | server_ip | /hello | client_ip |
+-------------+-------------+---------+-----------------+
3) The server is receives request and makes response back to load balancer. X-Forwarded-For
remains the same.
+-----------+-------------+------------------+-----------------+
| Source | Destination | Response | X-Forwarded-For |
+-----------+-------------+------------------+-----------------+
| server_ip | balancer_ip | response_message | client_ip |
+-----------+-------------+------------------+-----------------+
4) Balancer receives response from server and creates its own response back to client, by taking client's ip-address from X-Forwarded-For
header and putting it into destination:
+-------------+-------------+------------------+
| Source | Destination | Response |
+-------------+-------------+------------------+
| balancer_ip | client_ip | response_message |
+-------------+-------------+------------------+
Suppose all communcation is performed in HTTP. Is this a correct way of performing redirects between client - load balancer - server? I have looked through standard request/response fields and X-Forwarded-For
wasn't in the list of standard and non-standard responses. Also if this is the correct way, won't such popular frameworks such as Spring, Django, Node.js discard X-Forwarded-For
header?
networking ip routing load-balancer
networking ip routing load-balancer
asked Jan 8 at 5:14
TeamBeamTeamBeam
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