Load Balancer Flashcards
This algorithm sends traffic to a list of servers in rotation using the Domain Name System (DNS).
Round robin
This algorithm distributes tasks based on a threshold value that is set by the administrator.
Threshold
The “power of two” algorithm selects two servers at random and sends the request to the one that is selected by then applying the Least Connections algorithm or the Least Time algorithm, if so configured.
Random with two choices
A new request is sent to the server with the fewest current connections to clients. The relative computing capacity of each server is factored into determining which one has the least connections or which is using the least amount of bandwidth or resources.
Least connections
In this algorithm, a request is sent to the server selected by a formula that combines the fastest response time and fewest active connections.
Least time
This algorithm generates a hash value based on the URL present in client requests. The requests are forwarded to servers based on the hash value. The load balancer caches the hashed value of the URL, so subsequent requests that use the same URL result in a cache hit and are forwarded to the same server.
URL hash
This algorithm uses the client’s source and destination IP addresses to generate a unique hash key to tie the client to a particular server. As the key can be regenerated if the session disconnects, this allows reconnection requests to get redirected to the same server used previously.
Source IP hash
This algorithm maps both clients and servers onto a ring structure, with each server assigned multiple points on the ring based on its capacity. When a client request comes in, it is hashed to a point on the ring, and is then dynamically routed clockwise to the next available server.
Consistent hashing
Load balancers are generally used at Layer _ and Layer _ of the Open System Interconnection (OSI) model
Load balancers are generally used at Layer 4 and Layer 7.
Layer 4 load balancers direct traffic based on data from network and transport layer protocols (IP, TCP, FTP, UDP). Load balancing at the IP layer refers to a deployment where the load balancer’s IP address is the one advertised to clients for a website, and therefore recorded as the destination address. When the load balancer gets the request, it changes the recorded destination IP address to that of the content server it has chosen.
Layer 7 load balancers distribute requests based upon data found in application layer protocols such as HTTP headers, cookies, uniform resource identifier, SSL session ID, and HTML form data. They also enable routing decisions based on data within the application message itself, such as the value of a specific parameter. Layer 7 adds content switching to load balancing.
Layer _ load balancers direct traffic based on data from network and transport layer protocols (IP, TCP, FTP, UDP). Load balancing at the IP layer refers to a deployment where the load balancer’s IP address is the one advertised to clients for a website, and therefore recorded as the destination address. When the load balancer gets the request, it changes the recorded destination IP address to that of the content server it has chosen.
Layer 4 load balancers direct traffic based on data from network and transport layer protocols (IP, TCP, FTP, UDP). Load balancing at the IP layer refers to a deployment where the load balancer’s IP address is the one advertised to clients for a website, and therefore recorded as the destination address. When the load balancer gets the request, it changes the recorded destination IP address to tha
Layer _ load balancers distribute requests based upon data found in application layer protocols such as HTTP headers, cookies, uniform resource identifier, SSL session ID, and HTML form data. They also enable routing decisions based on data within the application message itself, such as the value of a specific parameter. Layer _ adds content switching to load balancing.
Layer 7 load balancers distribute requests based upon data found in application layer protocols such as HTTP headers, cookies, uniform resource identifier, SSL session ID, and HTML form data. They also enable routing decisions based on data within the application message itself, such as the value of a specific parameter. Layer 7 adds content switching to load balancing.
With users and customers around the world, companies can enhance their load availability with g____ s____ load balancing, which sends users to the nearest endpoint to them.
With users and customers around the world, companies can enhance their load availability with global server load balancing, which sends users to the nearest endpoint to them.
The technique for distributing traffic across multiple web or application server groups to optimize resource utilization is called H___(S) load balancing.
The technique for distributing traffic across multiple web or application server groups to optimize resource utilization is called HTTP(S) load balancing.
A type of load balancer that combines hardware and software load balancers is a v____ load balancer. It uses application delivery controller software that helps to distribute network traffic load among hardware backend servers.
A type of load balancer that combines hardware and software load balancers is a virtual load balancer. It uses application delivery controller software that helps to distribute network traffic load among hardware backend servers.
