I've created a L4 load balancer on GCE - where it should have been L7. Is there a way to change it to http/https load balancer anyhow?
Or create a new one, but transfer the IP address to the old one?
Related
I just started learning load balancers. Taking a server side application (http/https) load balancer as an example, I assume it listens a specific ip address, then forward the http requests to available servers based on its algorithm.
So is it possible for a load balancer to become a bottleneck? Because it's listening a specific ip address, all requests will first go to the single load balancer. So I think there could be a scenario where the amount of traffic is beyond the limit/capacity of the load balancer.
When it becomes a bottleneck, what can we do? Can we use multiple load balancers?
I think one possible solution is to use multiple load balancers and expose all the ips to clients. (This sounds like client side load balancing) So when a client wants to send a request, it can pick from the ip pool and then send a request to one of the load balancers. (For example, ZooKeeper could be used here.) Is this a working solution? Is there any other way to use multiple load balancers?
Thanks.
Ethan
Your last suggestion works with adding a little twist: The usual approach is to publish the load balancer IP addresses under the same domain name.
This is called DNS load balancing. Clients will ask for the IP resolution for your load balancer's domain name and they will get different IP addresses on a round-robin fashion.
To configure DNS load balancing you have to add multiple A records for your load balancer's domain name to your DNS configuration. Here you can find an example guide for that.
Following along from the Use a static IP address with the Azure Container Service (AKS) load balancer documentation I have created a static IP and assigned it to the load balancer. This worked fine on the initial run, but now I am getting the following error and the external ip for my load balancer is stuck <pending> (personal info omitted):
Failed to ensure load balancer for service default/[...]: network.LoadBalancersClient#CreateOrUpdate: Failure responding to request: StatusCode=400 -- Original Error: autorest/azure: Service returned an error. Status=400 Code="PublicIPReferencedByMultipleIPConfigs" Message="Public ip address /subscriptions/[...]/providers/Microsoft.Network/publicIPAddresses/[PublicIPName] is referenced by multiple ipconfigs in resource
As far as I can tell, this isn't referenced by multiple configs - just the load balancer service that I'm trying to run. Removing the loadBalancerIP option from my yaml file allows this to work but then I don't think the server address is static - which is not ideal for the applications trying to communicate with this container
Is this supposed to be happening? Is there a way to configure this so that the same IP can be reused after the container restarts?
Seeing as this issue appears to still be present, for anyone else stumbling upon this issue it seems that the Azure load balancer resource itself may be taking the first configured static IP address.
GitHub issue response:
the first public IP address created is used for egress traffic
Microsoft Docs:
Once a Kubernetes service of type LoadBalancer is created, agent nodes are added to an Azure Load Balancer pool. For outbound flow, Azure translates it to the first public IP address configured on the load balancer.
As far as I can tell, once you provision an IP address and configure an AKS load balancer to use it, that IP gets picked up by the provisioned load balancer resource in Azure. My best guess is that when Kubernetes attempts to provision a new load balancer with the same IP address, if the previous Azure load balancer still exists the IP config will fail as it's still in use.
Workaround was to provision an extra static IP (one specifically for the Azure load balancer resource, and one for the actual AKS load balancer service) to avoid conflicts. It's obviously not ideal but it solves the issue...
We use apache httpd load balancer for our project.
We were looking at Google Load balancer and may be shift to it.
But i dont find any comparison of both as in pro/con of one over another, so that we can decide on what suits as best.
Can we get a list of pro/con?
If scalability and performance is critical to you, definitely choose GCE load balancer. The traditional model of load balancing is basically "proxy + backends", in which the proxy quickly becomes the bottleneck. This is not the case for GCE load balancer, which has no proxy at all, the load balancing is implemented by the underlying infrastructure.
But GCE load balancer is not free, see pricing here https://cloud.google.com/compute/pricing#lb.
I am new to Google compute engine and I am try to setup network load balancing having 2 VMs for serving web pages.
For ex, I have 2 VMs - app1 and app2 - both having apache server and serves simple web page.
Both VMs are running with Red Hat Enterprise Linux Server release 7.0 (Maipo)
I am able to access both web pages through the IP in browser.
I created network load balancing setup and both apps are showing in green in target pool which means load balancer is able to connect to both VMs.
But, when I hit the IP of load balancer, it is rendering page from only one server. If I manually stop the server in the VM, load balancer IP redirects to other app. I believe load balancer is able to identify health of both VMs and able to redirect.
But it is not balancing the traffic. Can anyone help me to solve this issue?
I think that the network load balancer doesn't forward the traffic on a round-robin basis. I was able to test it with the load balancer setup that I have. As per the documentation:
By default, to distribute traffic to instances, Google Compute Engine picks an instance based on a hash of the source IP and port and the destination IP and port.
HTTP/S load balancing will proxy requests in a round-robin fashion. https://cloud.google.com/compute/docs/load-balancing/http/
I need to know the difference between a load balancer and load balancing.
Load balancing is the functionality provided by a Load balancer :).
In software architecture, a load balancer proxies client requests to a pool of application server, using an algorithm, with the objective of balancing the load of client requests evenly across the pool
Load balancing refers to efficiently distributing incoming network traffic across a group of backend servers, also known as a server farm or server pool.
A load balancer acts as the “traffic cop” sitting in front of your servers and routing client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance. If a single server goes down, the load balancer redirects traffic to the remaining online servers. When a new server is added to the server group, the load balancer automatically starts to send requests to it.
refer - https://www.nginx.com/resources/glossary/load-balancing/
Load Balancing helps spread incoming request traffic across cluster of servers. If a server is not availble to take a request, load balancer passes this request to another server.
Load Balancer in turn are the ones which achieve above, they could come in between :-
User - webserver
Webserver - internal application servers
Internal servers - database servers
Application servers - cache servers
Different types of Load Balancers:
Smart Client - Adding load balance achievability by It is a client which takes a pool of service hosts and balances load across them, detects downed hosts and avoids sending requests their way.
Hardware Load Balancer - Buy your own dedicated high performance server eg. Citrix NetScaler.
Software Load Balancer - Buy a software load balancer to overcome all the pain of building your own smart client or if you not ready spending on dedicated server. Cost effective than above two is buying a software load balancer eg. VmWare, HAProxy etc
As per my knowledge both are same but you can say that the load balancer is the device used for balancing the traffic as per the availability of the server and load balancing is nothing but theoretical explanation for how to achieve this.
Please correct me if I'm wrong!