kloudbuster/doc/source/usage.rst

Usage

There are three ways for running KloudBuster, the easiest being the Web UI. It offers the most user friendly interface and needs the least learning to get started. CLI is the traditional way to run applications. It has the most comprehensive feature sets when compared to the other two ways. Rest API gives another way to access and control KloudBuster from another application. All APIs provided are well documented, and the built-in web UI is fully implemented on top of these APIs.

The default scale settings of KloudBuster is at minimal scale, which is generally safe to run on any cloud, small or large. It should also work on an all-in-one devstack cloud installation as well. The minimal pre-requisites to run KloudBuster:

• Admin access to the cloud under test
• 3 available floating IPs

Running KloudBuster as a Web Server

The easiest way to use KloudBuster is to run it as a web server application. The KloudBuster qcow2 image has the Web server built-in and is ready to use once up running. To get the KloudBuster Web serverI running from scratch:

1. Follow the steps here <upload_kb_image> to upload the KloudBuster image to the openstack cloud that will host your kloudbuster web server (note that this could be the same as the cloud under test or could be a different cloud)

2. If necessary, and as for any web server bringup, create and configure the Neutron router and network where the KloudBuster web server VM instance will be attached

3. Create or reuse a security group which allows the ingress TCP traffic on port 8080

4. Launch an instance using the KloudBuster image，with the proper security group and connect to the appropriate network. Leave the Key Pair as blank, as we don't need the SSH access to this VM

5. Associate a floating IP to the newly created VM instance so that it can be accessible from an external browser

6. Open your browser, and type the below address to get started:

   http://<floating_ip>:8080/ui/index.html

Alternatively, you could also run KloudBuster as a local web server from a clone of the KloudBuster git repository. The Web UI is developed using AngularJS framework, which needs to be built before serving. If you want the web app to run on localhost, you have to build it from source, and start the KloudBuster server. Refer to here <build_web_ui> for the steps to build the web app, and refer to below section <start_kloudbuster_server> for the steps to start the KloudBuster server.

Running KloudBuster with CLI

KloudBuster needs the access info and the credentials to the cloud uner test, and these information can be downloaded from a Horizon dashboard (ProjectDownload OpenStack RC File). Save it to your local filesystem for future use.

KloudBuster is ready to run with the default configuration, which can be displayed from the command line using --show-config option. By default, KloudBuster will run on a single cloud mode and create:

• 2 tenants, 2 users, and 2 routers;
• 1 shared network for both servers and clients tenants
• 1 VM running as an HTTP server
• 1 VM running the Redis server (for orchestration)
• 1 VM running the HTTP traffic generator (default to 1000 connections, 1000 requests per second, and 30 seconds duration)

Run kloudbuster with the following options:

kloudbuster --tested-rc <path_to_the_admin_rc_file> --tested-passwd <admin_password>

The run should take couple of minutes (depending on how fast of the cloud to create resources) and you should see the actions taken by KloudBuster displayed on the console. Once the test is done, all resources will be cleaned up and results will be displayed.

Once this minimal scale test passes, you can tackle more elaborate scale testing by increasing the scale numbers or providing various traffic shaping options. See below sections for more details about configuring KloudBuster.

Configure KloudBuster

Usually, we can create our own configuration file based on the default by redirecting the output of --show-config to a new file. Modify the new file to satisfy our own needs, and pass it to the KlousBuster command line using the --config.

Note

Note that the default configuration is always loaded by KloudBuster and any default option can be overridden by providing a custom configuration file that only contains modified options.

Each item in cfg.scale.yaml is well documented and self-explained. Below is just a quick-start on some important config items that need to be paid more attention.

• vm_creation_concurrency

This controls the level of concurrency when creating VMs. There is no recommended values, as it really varies and up to the cloud performance. On a well-deployed cloud, you may able to push the values to more than 50. Safely to say, 5 would be OK for most deployments.

Note

For deployment prior to Kilo release, you may hit this bug if the concurrency level is too high. Try to lower down the value if you are hitting this issue.

• server:number_tenants, server:routers_per_tenant, server:networks_per_router, server:vms_per_network

These are the four key values which controls the scale of the cloud you are going to create. Depends on how you want the VM to be created, sets these values differently. For example, if we want to create 180 Server VMs, we could do either of the following settings:

(1) 30 tenants, 1 router per tenant, 2 networks per router, and 3 VMs per network (so-called 30*1*2*3);

(2) 20 tenants, 3 routers per tenant, 3 networks per router, and 1 VMs per network (so-called 20*3*3*1);

• server:secgroups_per_network

Reference Neutron router implementation is using IPTABLES to perform security controls, which should be OK for small scale networks. This setting for now is to investigate the upper limit capacity that Neutron can handle. Keep the default to 1 if you don't have the concerns on this part yet.

• client:progression

KloudBuster will give multiple runs (progression) on the cloud under this mode.

If enabled, KloudBuster will start the testing with certain amount of VMs specified by vm_start. For each iteration, KloudBuster will putting more VMs into the testing (specified by vm_step). The iteration will continue until it reaches the scale defined in the upper sections, or the stop limit.

The stop limit is used for KloudBuster to determine when to stop the progression, and do the cleanup if needed earlier. It defines as: [number_of_err_packets, percentile_of_packet_not_timeout(%)].

For example: [50, 99.99] means, KloudBuster will continue the progression run only if ALL below conditions are satisfied:

1. The error count of packets are less or equal than 50;
2. 99.99% of the packets are within the timeout range;

• client:http_tool_configs

This section is IMPORTANT, as it controls how the HTTP traffic will be generated. Below are the two values which determines the traffic:

# Connections to be kept concurrently per VM
connections: 1000
# Rate limit in RPS per client (0 for unlimited)
rate_limit: 1000

Each testing VM will have its targeting HTTP server for sending the requests. Simply to say, connections determines the how many concurrent users that the tool is emulating, and rate_limit determines how fast the HTTP request will be sent. If the connections are more than the capacity of the cloud can handle, socket errors or timeouts will occur; if the requests are sending too fast, you will likely to have lots of requests responded very slow (will be reflected in the latency distribution spectrum generated by KloudBuster).

Different cloud has different capacity to handle data plane traffics. The best practice is to have an estimate first, and get started. In a typical 10GE VLAN deployment, the line rate is about 9Gbps, or 1.125 GB/s. For pure HTTP traffic, the effective rate minus the overhead is approximately 80% of the line rate, which is about 920 MB/s. Each HTTP request will consume 32KB traffic for loading the HTML page (HTML payload size is configurable), so the cloud capacity is about 30,000 req/sec. If you are staging a cloud with 20 testing pairs, the rate_limit for each VM settings will be about (30000 / 20 = 1500).

The capacity for handling connections varies among factors including kernel tuning, server software, server configs, etc. and hard to have an estimate. It is simple to start with the same count as the rate_limit to have (1 request/connection) for each VM, and we can adjust it later to find out the maximum value. If you see socket errors or timeouts, means the scale you are testing is more than the cloud capacity.

Some other values which are self-explained, and you can change them as needed.

Advanced Features

Control the VM Placement

By default, VMs are placed by NOVA using its own scheduling logic. However, traffic can be shaped precisely to fill the appropriate network links by using specific configuration settings. KloudBuster can change that behavior, and force NOVA to place VMs on desired hypervisors as we defined by supplying the topology file.

The format of the topology file is relatively simple, and group into two sections. See file "cfg.topo.yaml" for an example.

The "servers_rack" section contains the hypervisors that the server side VMs will be spawned on, and the "clients_rack" section contains the hypervisors that the client side VMs will be spawned on. The hypervisor names can be obtained from Horizon dashboard, or via "nova hypervisor-list". Note that the name in the config files must exactly match the name shown in Horizon dashboard or NOVA API output.

A typical use case is to place all server VMs on one rack, and all client VMs on the other rack to test Rack-to-Rack performance. Similarly, all server VMs on one host, and all client VMs on the other host to test the Host-to-Host performance.

To use this feature, just pass -t <path_to_topo_file> to the kloudbuster command line.

Note

Admin access is required to use this feature.

Running KloudBuster without admin access

When there is no admin access to the cloud under test, KloudBuster does support to run and reused the existing tenant and user for running tests. You have to ask the cloud admin one time to create the resources in advance, and KloudBuster will create the resources using the pre-created tenant/user.

When running under the tenant/user reusing mode:

• Only one tenant will be used for hosting both server cloud and client cloud resources;
• Only two users will be used for creating resources, and each cloud has its own user;

And also there are some limitations that you should aware:

• The VM placement feature will not be supported;
• The flavor configs will be ignored, and the KloudBuster will automatically pick the closest flavor settings from the existing list;
• KloudBuster will not automatically adjust the tenant quota, and give warnings when quota exceeded;

See file "cfg.tenants.yaml" for an example. Modify the settings to match your cloud.

To use this feature, just pass -l <path_to_tenants_file> to the kloudbuster command line.

Examples of running KloudBuster

Assuming the OpenStack RC file is stored at ~/admin_openrc.sh, and the password is "admin". Running the program is relatively easy, some examples are given to help get started quickly.

Note

Before going to large scale test, it is strongly recommended to start with a small scale. The default config is a good point to start with. It will make sure KloudBuster is talking to the clouds well.

Example 1: Single-cloud Mode

Kloudbuster will create both server VMs and client VMs in the same cloud if only one RC file is provided:

$ kloudbuster --tested-rc ~/admin_openrc.sh --tested-passwd admin

Example 2: Dual-cloud Mode, Save results

Assume the cloud for server VMs is ~/admin_openrc1.sh, and the cloud for client VMs is ~/admin_openrc2.sh. The password for both clouds is "admin". Also save the results to a JSON file once the run is finished:

$ kloudbuster --tested-rc ~/admin_openrc1.sh --tested-passwd admin --testing-rc ~/admin_openrc2.sh --testing-passwd admin --json result.json

Example 3: Single-cloud Mode, Customized VM placements

$ kloudbuster --tested-rc ~/admin_openrc.sh --tested-passwd admin -t cfg.topo.yaml

Interpret the Results

KloudBuster does come with a good Web UI to display the results in a pretty graphical way. However, in the case if you are not using the Web UI, KloudBuster also has a small tool locally to generate the chart. It accepts JSON files generated by KloudBuster. To see the chart in HTML, simply run:

$ kb_gen_chart -c <HTML_FILANAME_TO_SAVE> <JSON_FILE>

Check:

$ kb_gen_chart -h

for more options.

Running with Rest API

All Rest APIs are well documented using Swagger. In order to view them in a nice format, copy the entire contents of file kb_server/kloudbuster-swagger.yaml, and paste into the left panel of http://editor.swagger.io. Then you will see the specification of all Rest APIs in the right panel of the web page.

KloudBuster integrates a Python based web server Pecan to host both the KloudBuster Rest API server and the KloudBuster front-end website, which listens to localhost:8080 by default.

From the root of the KloudBuster repository, go to kb_server directory. If this is the first time to start the server, run below command once to setup the environment:

$ python setup.py develop

Then start the server by doing:

$ pecan serve config.py

Idealy, you should see a message like below, which indicates the server is up running:

Starting server in PID 26431
serving on 0.0.0.0:8080, view at http://127.0.0.1:8080

Once the server is started, you can use different HTTP methods (GET/PUT/POST/DELETE) to interactive with KloudBuster.

KloudBuster Standard Scale Profile

Multiple factors can impact data plane scale numbers measured by KloudBuster: VM count, number of connections per VM, number of requests per seconds per VM, timeout, etc... To help obtaining quick and easy results without having to tweak too many parameters, KloudBuster defines an off the shelf default scale profile.

In the default scale profile:

• the number of connections per VM will be set to 1000,
• the number of requests per seconds per VM is set to 1000,
• the HTTP request timeout is set to 5 seconds.
• the stop limit for progression runs will be error packets greater than 50.
• The size of the HTML page in the server VMs will be 32768 Bytes.

In order to perform a run using the default scale profile, set the max VM counts for the test, enable progression run and leave everything else with their default values. KloudBuster will start the iteration until reaching the stop limit or the max scale. Eventually, once the KloudBuster run is finished, the cloud performance can be told by looking at how many VMs KloudBuster can run to and by looking at the latency charts.

As a reference, KloudBuster can run approximately 21 VMs (with 21,000 connections and 21,000 HTTP requests/sec) and achieve approximately 5 Gbps of HTTP throughput on a typical multi-node Kilo OpenStack deployment (LinuxBridge + VLAN, 10GE NIC card).

How-to

In order to run KloudBuster Standard Scale Profile, you have to set up below configurations:

1. Enable progression runs:

   Running from CLI: Edit the config file, and set client:progression:enabled to True

   Running from Web UI: Navigate to "Interactive Mode" from the top menu bar, unfold the left panel for detail settings, under "Progression Test" section, and check the "Progression Test" checkbox.

2. Set up the max scale:

   The max scale basically means the max VM counts that KloudBuster will try to reach. For a typical 10GE NIC card with VLAN encapsulation, 25 will be a good value. Adjust it to a reasonable value based on your deployment details.

   Running from CLI: Edit the config file, and set server:vms_per_network to a proper value.

   Running from Web UI: Navigate to "Interactive Mode" from the top menu bar, unfold the left panel for detail settings, under "Staging Settings" section, and set "VMs/Network" to a proper value.

Interpret the results

From the CLI, check the log and find the warning that KloudBuster gave, similar to this:

WARNING KloudBuster is stopping the iteration because the result reaches the stop limit.

One line before is the json output of last successful run, which has the number in the "total_server_vms" field.

From the Web UI, in ihe "Interactive Mode" tab, you will see how many sets of data are you getting. The second last set of data shows the last successful run, which has the number in the "Server VMs" column.