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. The built-in Web UI is fully implemented on top of the REST API.

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 (non-admin might work with some tweaks and limitations)
• 3 available floating IPs if running HTTP data plane testing, 2 available floating IPs if running Storage testing

Regardless of the way you launch KloudBuster, you will need the access info and the credentials to the cloud under test. This information can be downloaded from a Horizon dashboard (ProjectApi Access|Download OpenStack RC File). Save it to your local filesystem for future use.

Running KloudBuster as a Web/REST Server

Starting the KloudBuster Server from a VM Image

The easiest way to use KloudBuster is to run it as a web server application running in a VM. The pre-built KloudBuster qcow2 image contains the Web server and is ready to service HTTP and REST requests once up and running. To get the KloudBuster Web server running in any OpenStack cloud:

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

This could be the same as the cloud under test or a different cloud.

2. If necessary, and as for any VM-based web server application 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 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

The base URL to use for REST access is:

http://<floating_ip>:8080

The Web UI URL to use from any browser is:

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

Starting the KloudBuster Server from PyPI installation

From the virtual environment which hosts KloudBuster, run:

$ kb_start_server

You should see a message similar to the one below, which indicates the server is up running:

Starting server in PID 27873
serving on 0.0.0.0:8080, view at http://127.0.0.1:8080

Starting the KloudBuster Server from a git clone

If you use git clone, you can bring up the KloudBuster Web/REST server fron the CLI. KloudBuster uses the Pecan web server to host both the KloudBuster REST server and the KloudBuster front-end website (which listens to port 8080 by default).

From the root of the KloudBuster repository, go to the 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

You should see a message similar to the one 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

Using the KloudBuster Web UI

Using any browser, point to the provided URL at port 8080. You will get a Login page where you will need to enter:

• The type of scale test (HTTP data plane or storage)
• The location of openrc file of the cloud under test
• The credentials for the cloud under test

Interacting with the KloudBuster Server REST Interface

Once the server is started, you can use different HTTP methods (GET/PUT/POST/DELETE) to interact with the KloudBuster REST interface using the provided URL at port 8080.

• KloudBuster REST API Documentation Preview
• REST API Documentation (Swagger yaml)

Running the KloudBuster from CLI

If you do not really need a Web UI or REST interface, you can simply run KloudBuster scale test straight from CLI.

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 and run the default HTTP data plane scale test:

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

Run KloudBuster with the following options:

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

Note

Simply adding --storage to the above command will run KloudBuster with storage testing.

The run should take couple of minutes (depending on how fast the cloud can create the resources) and you should see the actions taken by KloudBuster displayed on the console. 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.

KloudBuster Configuration

To create a custom scale test configuration, make a copy of the default configuration and modify that file to satisfy our own needs. A copy of the default configuration can be obtained by redirecting the output of --show-config to a new file. Once done, provide that custom configuration file to the KloudBuster command line using the --config <file> option.

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. So you can delete all the lines in the configuration file that you do not intend to change

General 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 with certain amount of VMs, and put more VMs into the testing for every iteration. The increment of the VM count is specified by vm_multiple. 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.

In the case of HTTP testing:

It is 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;

In the case of Storage testing:

It is a single integer indicating the degrading percentile. In the mode of random read and random write, this value indicates the percentile of degrading on IOPS, while in the mode of sequential read and sequential write, this value indicates the percentile of degrading on throughput.

Assume the IOPS or throughput per VM is a fixed value, usually we are expecting higher values when the VM count grows. At certain point where the capacity of storage is reached, the overall performance will start to degrade.

e.g. In the randread and randwrite mode, for example the IOPS is limited to 100 IOPS/VM. In the iteration of 10 VMs, the requested IOPS for the system is 100 * 10 = 1000. However, the measured IOPS is degraded to only 800 IOPS. So the degraded percentile is calculated as 800/1000=20% for this set of data.

HTTP Tool Specific Options

• client:http_tool_configs

This section controls how the HTTP traffic will be generated. Below are the two values which determine 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.

Storage Tool Specific Options

• client:storage_tool_configs

This section controls how the Storage tests will be performed. All the fields are self-explained, and you can create your own test case with customized parameters.

• client:storage_target

KloudBuster supports to test the storage performance on Cinder volumes or ephemeral disks. Specify the testing target here.

• client:disk_size

This controls the size of the Cinder volume or ephemeral disk to be attached to each VM instance. (in GB)

• client:io_file_size

This controls the size of the test file to be used for storage testing. (in GB)

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.

Displaying the Results

Results can be saved in a file in json format or in html format. The json format is more appropriate for usage by any post-processing tool or script while the html file is more adapted for human usage.

The KloudBuster Web UI will display the results using charts and tables when the test is finished running. The KloudBuster CLI provides an option to generate the html file from the results (--html option). It can also generate the html file from the json results (--charts-from-json option).

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

Example 4: Single-cloud Mode, Running storage test, Save results to JSON

$ kloudbuster --tested-rc ~/aio-openrc.sh --tested-passwd lab --storage --json aio.json

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 for running HTTP load:

• The number of connections per VM is 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;

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).

In the default scale profile for running Storage load:

• A standard set of 6 test cases (random read/write/mixed, sequential read/write/mixed);
• The IOPS limit per VM is set to 100 for random read/write/mixed test cases, and Rate limit per VM is set to 60MB/s for sequential read/write/mixed test cases;
• Block size is set to 4K for random read/write/mixed test cases, and 64K for sequential read/write/mixed test cases;
• IO Depth is set to 4 for random read/write/mixed test cases, and 64 for sequential read/write/mixed test cases;
• The stop limit for progression runs is degrading more than 20% of the target;

Note that it is hard to give a reference on storage testing since the performance varies a lot on different hardware or solutions.

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.

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. In the case of HTTP testing, for a typical 10GE NIC card with VLAN encapsulation, 25 will be a good value; in the case of Storage testing, depends on the solution the deployment is using, pick a number from 10 to 25 would usually be fine. Remember you can always adjust it to a more 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.