Gobalan is a TCP load balancer that supports high network throughput and also support a special load balancing algorithm based on the machine performance.It is a per-connection load balancer.
Next are some concepts for gobalan:
Workere Service is used for representing tcp services need to be load balanced.
Worker runs on a machine for Worker Service's health check and monitoring the load of the machine(e.g. CPU usage rate,Memory usage rate and network IO usage rate).It reports the above information to Master at some specified time interval.
Master is used for collecting Worker Services' health information and machine load information.It also provides service for client to pick a proper worker node using the configured load balance algorithm.
Look at the above picture,it describes how gobalan works:
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Firstly, start Master node and all the Workers nodes,then workers will establish connections with Master, then send relevant information including health check information and machine load information to Master.
Master will register the load balance algorithms for the next picking.
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Secondly,when a client needs to request Worker Service,it will firstly request the Master to pick a proper worker node using the configured load balance algorithm.
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Thirdly,after the client gets the Worker Service's ip and port,the client will establish a connection with the selected worker node and then proceed with the service request.
Now gobalan supports two load balance algorithms:
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RoundRobin It is a tranditional load balance algorithm.
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OptimalPerformance Now the machine performance scoring formula is:
score = cpu usage rate + memory usage rate + networkIO read rate + networkIO write rate
The lower score and the better performance.
You can even implement your own load balance algorithm based on the gobalan framework.
We need to do some configurations for Worker and Master,the configuration file config.ini is under config folder.
; Load Balance Master configurations.
[Master]
; Use the current server as a master or not.
IsMaster = true
; The port that will be connected by workers and clients.
Port = 5388
; Load balancing algorithm
; [0] Roundrobin abbr RR
; [1] OptimalPerformance abbr OP
LBAlgorithm = OP
The Master section is used for master configuration:
- IsMaster If you use the current machine as a gobalan master then set it to true or else set it to false.
- Port The port is the master service port for collecting workers' information and picking worker node for clients.
- LBAlgorithm Use this option to specify load balance algorithm.Here we use the abbreviation of algorithms, that is OP or RR.
; Load Balance Worker configurations.
[Worker]
; Use the current server as a worker or not.
IsWorker = false
; The Master IP that current worker will connect to.
MasterIP = 192.0.2.62
; The Master port that current worker will connect to.
MasterPort = 5388
; The service port monitored by worker.
ServicePort = 143
; The heartbeat sending interval (seconds) used by worker.
HeartbeatInterval = 5
; Load report parameters about worker.
[Worker.LoadReport]
; The worker server load report interval (seconds).
LoadReportInterval = 60
; Max network bandwidth(Mb)
MaxNetworkBandwidth = 100
; The adapter name monitored by worker
NetworkAdapterName = eth0
The worker section is used for worker configuration:
- IsWorker If you use the current machine as a gobalan worker then set it to true or else set it to false.
- MasterIP Specify master IP that the current worker will connect to.
- MasterPort Specify the master port that the current worker will connect to.
- ServicePort The ServicePort is the Port of Worker Service which is run on worker machine.
- HeartbeatInterval Specify the heartbeat time interval.
The section Worker.LoadReport is the child section of Worker:
- LoadReportInterval Specify the machine load report time interval.
- MaxNetworkBandwidth Provide the current maximum network bandwidth.
- NetworkAdapterName Specify the network adapter used by current machine.
The Steps are as follows:
- You should install gobalan on the machine running Worker Service as a worker and also install it on another machine as a master.
- Do some configuratinos accrording to Configurations.
- Start both the worker and master service.
- You need to do some extra development work to request master and parse the result for getting the real service IP and port.
- grpc-go gobalan uses grpc-go as network communication framework.
- statgo gobalan uses statgo to read the machine load in real time,bacause it is a libstatgrab binding for Golang, so you should install the library on your work OS.