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-rw-r--r--docs/userguide/low_latency.userguide.rst179
1 files changed, 166 insertions, 13 deletions
diff --git a/docs/userguide/low_latency.userguide.rst b/docs/userguide/low_latency.userguide.rst
index 66e63770c..e65c8aa4f 100644
--- a/docs/userguide/low_latency.userguide.rst
+++ b/docs/userguide/low_latency.userguide.rst
@@ -48,15 +48,19 @@ Please check the default kernel configuration in the source code at:
kernel/arch/x86/configs/opnfv.config.
Below is host kernel boot line example:
-::
-isolcpus=11-15,31-35 nohz_full=11-15,31-35 rcu_nocbs=11-15,31-35
-iommu=pt intel_iommu=on default_hugepagesz=1G hugepagesz=1G mce=off idle=poll
-intel_pstate=disable processor.max_cstate=1 pcie_asmp=off tsc=reliable
+
+.. code:: bash
+
+ isolcpus=11-15,31-35 nohz_full=11-15,31-35 rcu_nocbs=11-15,31-35
+ iommu=pt intel_iommu=on default_hugepagesz=1G hugepagesz=1G mce=off idle=poll
+ intel_pstate=disable processor.max_cstate=1 pcie_asmp=off tsc=reliable
Below is guest kernel boot line example
-::
-isolcpus=1 nohz_full=1 rcu_nocbs=1 mce=off idle=poll default_hugepagesz=1G
-hugepagesz=1G
+
+.. code:: bash
+
+ isolcpus=1 nohz_full=1 rcu_nocbs=1 mce=off idle=poll default_hugepagesz=1G
+ hugepagesz=1G
Please refer to `tuning.userguide` for more explanation.
@@ -68,45 +72,194 @@ environment is also required. Please refer to `tunning.userguide` for
more explanation.
Test cases to measure Latency
-=============================
+-----------------------------
+The performance of the kvmfornfv is assesed by the latency values. Cyclictest and Packet forwarding
+Test cases result in real time latency values of average, minimum and maximum.
+
+* Cyclictest
+
+* Packet Forwarding test
-Cyclictest case
----------------
+1. Cyclictest case
+-------------------
+Cyclictest results are the most frequently cited real-time Linux metric. The core concept of Cyclictest is very simple.
+In KVMFORNFV cyclictest is implemented on the Guest-VM with 4.4-Kernel RPM installed. It generated Max,Min and Avg
+values which help in assesing the kernel used. Cyclictest in currently divided into the following test types,
+
+* Idle-Idle
+* CPU_stress-Idle
+* Memory_stress-Idle
+* IO_stress-Idle
+
+Future scope of work may include the below test-types,
+
+* CPU_stress-CPU_stress
+* Memory_stress-Memory_stress
+* IO_stress-IO_stress
Understanding the naming convention
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. code:: bash
+
+ [Host-Type ] - [Guest-Type]
+
+* **Host-Type :** Mentions the type of stress applied on the kernel of the Host
+* **Guest-Type :** Mentions the type of stress applied on the kernel of the Guest
+
+Example.,
+
+.. code:: bash
+
+ Idle - CPU_stress
+
+The above name signifies that,
+
+- No Stress is applied on the Host kernel
+
+- CPU Stress is applied on the Guest kernel
+
+**Note:**
+
+- Stress is applied using the stress which is installed as part of the deployment.
+ Stress can be applied on CPU, Memory and Input-Output (Read/Write) operations using the stress tool.
+
+Version Features
+~~~~~~~~~~~~~~~~
+
++-----------------------+------------------+-----------------+
+| **Test Name** | **Colorado** | **Danube** |
+| | | |
++-----------------------+------------------+-----------------+
+| - Idle - Idle | ``Y`` | ``Y`` |
+| | | |
+| - Cpustress - Idle | | ``Y`` |
+| | | |
+| - Memorystress - Idle | | ``Y`` |
+| | | |
+| - IOstress - Idle | | ``Y`` |
+| | | |
++-----------------------+------------------+-----------------+
+
+
Idle-Idle test-type
~~~~~~~~~~~~~~~~~~~
+Cyclictest in run on the Guest VM when Host,Guest are not under any kind of stress. This is the basic
+cyclictest of the KVMFORNFV project. Outputs Avg, Min and Max latency values.
+
+.. figure:: images/idle-idle-test-type.png
+ :name: idle-idle test type
+ :width: 100%
+ :align: center
CPU_Stress-Idle test-type
--------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Here, the host is under CPU stress, where multiple times sqrt() function is called on kernel which
+results increased CPU load. The cyclictest will run on the guest, where the guest is under no stress.
+Outputs Avg, Min and Max latency values.
+
+.. figure:: images/cpu-stress-idle-test-type.png
+ :name: cpu-stress-idle test type
+ :width: 100%
+ :align: center
Memory_Stress-Idle test-type
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In this type, the host is under memory stress where continuos memory operations are implemented to
+increase the Memory stress (Buffer stress).The cyclictest will run on the guest, where the guest is under
+no stress. It outputs Avg, Min and Max latency values.
+
+.. figure:: images/memory-stress-idle-test-type.png
+ :name: memory-stress-idle test type
+ :width: 100%
+ :align: center
IO_Stress-Idle test-type
~~~~~~~~~~~~~~~~~~~~~~~~
+The host is under constant Input/Output stress .i.e., multiple read-write operations are invoked to
+increase stress. Cyclictest will run on the guest VM that is launched on the same host, where the guest
+is under no stress. It outputs Avg, Min and Max latency values.
+
+.. figure:: images/io-stress-idle-test-type.png
+ :name: io-stress-idle test type
+ :width: 100%
+ :align: center
CPU_Stress-CPU_Stress test-type
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Not implemented for Danube release.
Memory_Stress-Memory_Stress test-type
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Not implemented for Danube release.
IO_Stress-IO_Stress test type
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Not implemented for Danube release.
+
+2. Packet Forwarding Test cases
+-------------------------------
+Packet forwarding is an other test case of Kvmfornfv. It measures the time taken by a packet to return
+to source after reaching its destination. This test case uses automated test-framework provided by
+OPNFV VSWITCHPERF project and a traffic generator (IXIA is used for kvmfornfv). Only latency results
+generating test cases are triggered as a part of kvmfornfv daily job.
+
+Latency test measures the time required for a frame to travel from the originating device through the
+network to the destination device. Please note that RFC2544 Latency measurement will be superseded with
+a measurement of average latency over all successfully transferred packets or frames.
-Packet Forwarding Test case
----------------------------
+Packet forwarding test cases currently supports the following test types:
+
+* Packet forwarding to Host
+
+* Packet forwarding to Guest
+
+* Packet forwarding to Guest using SRIOV
+
+The testing approach adoped is black box testing, meaning the test inputs can be generated and the
+outputs captured and completely evaluated from the outside of the System Under Test(SUT).
Packet forwarding to Host
~~~~~~~~~~~~~~~~~~~~~~~~~
+This is also known as Physical port → vSwitch → physical port deployment.
+This test measures the time taken by the packet/frame generated by traffic generator(phy) to travel
+through the network to the destination device(phy). This test results min,avg and max latency values.
+This value signifies the performance of the installed kernel.
+
+Packet flow,
+
+.. figure:: images/host_pk_fw.png
+ :name: packet forwarding to host
+ :width: 100%
+ :align: center
Packet forwarding to Guest
~~~~~~~~~~~~~~~~~~~~~~~~~~
+This is also known as Physical port → vSwitch → VNF → vSwitch → physical port deployment.
+
+This test measures the time taken by the packet/frame generated by traffic generator(phy) to travel
+through the network involving a guest to the destination device(phy). This test results min,avg and
+max latency values. This value signifies the performance of the installed kernel.
+
+Packet flow,
+
+.. figure:: images/guest_pk_fw.png
+ :name: packet forwarding to guest
+ :width: 100%
+ :align: center
Packet forwarding to Guest using SRIOV
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+This test is used to verify the VNF and measure the base performance (maximum forwarding rate in
+fps and latency) that can be achieved by the VNF without a vSwitch. The performance metrics
+collected by this test will serve as a key comparison point for NIC passthrough technologies and
+vSwitches. VNF in this context refers to the hypervisor and the VM.
+
+**Note:** The Vsperf running on the host is still required.
+Packet flow,
+.. figure:: images/sriov_pk_fw.png
+ :name: packet forwarding to guest using sriov
+ :width: 100%
+ :align: center