You have deployed a new internal application that provides HTTP and TFTP services to on-premises hosts. You want to be able to distribute traffic across multiple
Compute Engine instances, but need to ensure that clients are sticky to a particular instance across both services.
Which session affinity should you choose?
To ensure that clients are sticky to a particular instance across both HTTP and TFTP services, the session affinity should be based on the Client IP. This is because you want to keep the communication consistent regardless of the protocol or port being used. By using Client IP affinity, all requests from the same client IP will be directed to the same backend instance, ensuring stickiness across the services.
The correct answer is B HTTP/S port 80/443 TFTP port 69 Session affinity, (sticky sessions), overrides the load-balancing algorithm by directing all requests in a session to a specific application server. So, we need a Session affinity by Client IP. Session affinity https://cloud.google.com/load-balancing/docs/backend-service#session_affinity Session affinity options https://cloud.google.com/load-balancing/docs/internal#session_affinity The answer A&D produces the same (Client IP, protocol, and port) by the way.
B. Client IP
Answer is B
this part of the question "but need to ensure that clients are sticky to a particular instance across both services." has to be client IP.. (B)
Thanks Sierra, i must of missed that part
B. Client IP In the context of session affinity, selecting "Client IP" means that the load balancer uses the client's IP address to determine which backend instance should receive the traffic. Each unique client IP is consistently directed to the same backend instance. If you are looking for stickiness based on the client's IP address only, and you don't need to consider the specific protocol (HTTP or TFTP), then option B is appropriate. So, if the requirement is solely to maintain stickiness based on the client IP and the protocol (HTTP or TFTP) doesn't need to be considered, then option B is indeed the correct choice. I appreciate your clarification, and I hope this provides a clear explanation.
should be D. the less metrics you choose, the lworse load balance among the instances. for example, for B, it is true that the session keep to the same instance, but it is always kept to the SAME instance only if the same source ip and destionation ip for the both protocols
why not D? The same client could be accessing both HTTP and FTP, so the session stickiness based on Client IP only is not enough.
on one more read, it is still ONE application that handles both services, so the Client IP is fine in that case.
If UDP packet exceeds frame size then it is fragmented by IP stack and only the first fragment has the port number, remaining fragments don't have the port number. With that said hashing by port does not work (does not make sense). Only valid option is B - hash by Client IP.
Question mentions about HTTPS i.e. TCP and TFTP i.e. UDP protocols in an internal load balancer so it's definitely provides Client IP, Protocol and IP as options. So answer D is correct. https://cloud.google.com/load-balancing/docs/backend-service#session_affinity
D shows: Client IP, port and protocol... only 3 out of 4. Where is the Destination IP? this also looks like c as well BUT without the comma...
If it was showing all 4 wouldn't look like: Client, IP, port and protocol? With 2 commas separating?
ANS is B. HTTP traffic uses TCP, TFTP uses UDP. Session Affinity does not work in UDP traffic, thus, using protocol and port is useless. Ref:https://cloud.google.com/load-balancing/docs/internal "Session affinity works on a best-effort basis for TCP traffic. Because the UDP protocol doesn't support sessions, session affinity doesn't affect UDP traffic."
Answer is B: https://medium.com/google-cloud/google-cloud-load-balancer-setup-tweaking-and-observations-c12d704e6d52' ffinity Typically the LB is going to route new requests to any instance and traffic from one connection is going to route to the same instance. Say you want to set stickiness to make sure all connections from one client go to the same instance. Configure session affinity to client IP. You can also set by cookie. The GCLB sends a cookie on the first client request and future incoming requests with that cookie will be sent to the same instance.
B is correct answer for me
Has to be D, cos no stated reason why http and tftp will always need to be served from the same machine as each other. Also you can serve either from any port, not just the defaults. So you need client, port and protocol tuple
this part of the question "but need to ensure that clients are sticky to a particular instance across both services." has to client IP.. (B)
D is the correct
Ans - B
Why not D, TFTP is UDP protocol
B is the one
Is the answers showing the syntax to use?
If you include more parameters than ClientIP then you will split workloads across servers between the 2 application endpoints.