From 4ee173564fcbcde8633c08cb49e22d9fe97c0f2e Mon Sep 17 00:00:00 2001
From: Graham Hayes <graham.hayes@hpe.com>
Date: Tue, 15 Sep 2015 16:57:54 +0100
Subject: [PATCH] Proposed Service Architecture for Kosmos
Also including the old massive overview .dot file,
its not referenced, but it might be handy in the future.
Change-Id: I68dc4521afe4efb520748fbc323867a045a2eb77
---
doc/source/conf.py | 3 +
doc/source/index.rst | 8 ++
requirements.txt | 4 +-
specs/mitaka/sysarch.rst | 133 ++++++++++++++++++
specs/mitaka/sysarch/erd-diagram.dot | 91 ++++++++++++
specs/mitaka/sysarch/example-flow.diag | 19 +++
.../sysarch/sysarch-diagram-conductor.dot | 34 +++++
.../mitaka/sysarch/sysarch-diagram-engine.dot | 34 +++++
.../sysarch/sysarch-diagram-overview.dot | 67 +++++++++
.../sysarch-diagram-status-checker.dot | 35 +++++
specs/mitaka/sysarch/sysarch-diagram.dot | 114 +++++++++++++++
11 files changed, 541 insertions(+), 1 deletion(-)
create mode 100644 specs/mitaka/sysarch.rst
create mode 100644 specs/mitaka/sysarch/erd-diagram.dot
create mode 100644 specs/mitaka/sysarch/example-flow.diag
create mode 100644 specs/mitaka/sysarch/sysarch-diagram-conductor.dot
create mode 100644 specs/mitaka/sysarch/sysarch-diagram-engine.dot
create mode 100644 specs/mitaka/sysarch/sysarch-diagram-overview.dot
create mode 100644 specs/mitaka/sysarch/sysarch-diagram-status-checker.dot
create mode 100644 specs/mitaka/sysarch/sysarch-diagram.dot
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 6c63134..9393a9c 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -26,6 +26,9 @@ extensions = [
#'sphinx.ext.intersphinx',
'oslosphinx',
'yasfb',
+ 'sphinx.ext.graphviz',
+ 'sphinxcontrib.seqdiag',
+ 'sphinxcontrib.httpdomain',
]
# Feed configuration for yasfb
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 2f254a8..807e149 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -14,6 +14,14 @@ Liberty approved specs:
specs/liberty/*
+Mitaka approved specs:
+
+.. toctree::
+ :glob:
+ :maxdepth: 1
+
+ specs/mitaka/*
+
kosmos-specs Repository Information
===================================================
diff --git a/requirements.txt b/requirements.txt
index 17a43bd..f6b236e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,6 @@
pbr>=0.11,<2.0
oslosphinx
sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
-yasfb>=0.5.1
\ No newline at end of file
+yasfb>=0.5.1
+sphinxcontrib-seqdiag
+sphinxcontrib-httpdomain
\ No newline at end of file
diff --git a/specs/mitaka/sysarch.rst b/specs/mitaka/sysarch.rst
new file mode 100644
index 0000000..0e4e34d
--- /dev/null
+++ b/specs/mitaka/sysarch.rst
@@ -0,0 +1,133 @@
+..
+
+This work is licensed under a Creative Commons Attribution 3.0 Unported License.
+http://creativecommons.org/licenses/by/3.0/legalcode
+
+..
+ This template should be in ReSTructured text. The filename in the git
+ repository should match the launchpad URL, for example a URL of
+ https://blueprints.launchpad.net/kosmos/+spec/awesome-thing should be named
+ awesome-thing.rst . Please do not delete any of the sections in this
+ template. If you have nothing to say for a whole section, just write: None
+ For help with syntax, see http://sphinx-doc.org/rest.html
+ To test out your formatting, see http://www.tele3.cz/jbar/rest/rest.html
+
+=====================
+ System Architecture
+=====================
+
+Overview
+========
+
+The system should be made up of a few services, that are small, and horizontally scalable.
+
+The system should be the following:
+- Scalable
+- Fault Tolerant
+- Use other OpenStack projects as first class citizens
+ - For the GSLB appliance drivers the default should be `Designate`_
+ - For regional pool members Neutron `LBaaS V2`_ should be the default
+
+.. note:: This is for the MVP. Post MVP we need to also be able to run as a global service.
+
+
+Overview Diagram
+----------------
+
+.. graphviz:: sysarch/sysarch-diagram-overview.dot
+
+
+Services
+--------
+
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| service name | deployment model | purpose | notes |
++=======================+=================================================+===============================================================================+===================================================================================================+
+| kosmos-api | multiple | Configuration of GSLBs | |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| kosmos-conductor | multiple - single region | Database Access | |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| kosmos-status-checker | multiple - global | Check status of endpoints | |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| kosmos-engine | multiple - single region | Business Logic | |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| GSLB Appliance | multiple - global (depending on appliance used) | Applicance that is used by Kosmos to direct traffic to the correct endpoints. | This is Designate in the reference Implementation |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+| Endpoints | multiple - multiple regions | The destination for the traffic that is being load balanced by Kosmos | This will be LBaaS V2 Load Balancers by default, but could also be IPs or Hardware Load Balancers |
++-----------------------+-------------------------------------------------+-------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------+
+
+kosmos-api
+^^^^^^^^^^
+
+The API would be a WSGI service that implements the API Spec previously approved.
+
+It should follow the standard OpenStack patterns (use Keystone / oslo.middleware / oslo.context)
+
+kosmos-conductor
+^^^^^^^^^^^^^^^^
+
+This will act as a single point of access to the DB, allowing for consistent data validation.
+
+As results are fed in from status-checkers, then engine will decide if an endpoint is suitable to be included in the pool. As it adds and removes nodes, it will
+update both the database, and the GSLB appliance, via the plugin. (e.g. if using the Designate plugin it would remove the endpoint's IP from the record)
+
+.. warning:: The logging component described below may be cut in the MVP
+
+There is a logging component that could be a separate DB, a timeseries DB, a columnar DB, elastic search or other storage system
+This will store a section of history for the pools, to allow users to see when / why endpoints were added / removed from the load balancer.
+
+.. graphviz:: sysarch/sysarch-diagram-conductor.dot
+
+kosmos-status-checker
+^^^^^^^^^^^^^^^^^^^^^
+
+This is a worker style service that will run status checks on the defined endpoints.
+
+This will have a plugin interface to allow for more checks to the loaded by different plugins, or for custom checks to be written by the deployer (using standard OpenStack plugin patterns)
+
+For example, any pool-members / endpoints that are LBaaS instances will not call into the VIP, but will call the LBaaS V2 API to get the health of the regional members.
+
+.. graphviz:: sysarch/sysarch-diagram-status-checker.dot
+
+kosmos-engine
+^^^^^^^^^^^^^
+
+This is where all the business logic resides. This service will consume status results and decide if an endpoint should be removed / added.
+This service will then use the plugin loaded for the GSLB backend to orchestrate this.
+
+The plugins will allow different types of GSLB appliances / services to be used, and will use standard OpenStack plugin patterns.
+
+.. graphviz:: sysarch/sysarch-diagram-engine.dot
+
+
+Entity Relationship Diagram
+---------------------------
+
+.. graphviz:: sysarch/erd-diagram.dot
+
+
+Example
+-------
+
+This is an example flow of information, when we are using Designate and checking the health info of a Neutron LBaaS load balancer.
+The plugin components are excluded for clarity, but would be between the "Status Check" and "Engine" components.
+
+.. seqdiag:: sysarch/example-flow.diag
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+ kosmos-drivers
+
+Milestones
+----------
+
+Target Milestone for completion:
+ M-2
+
+.. _Designate: http://wiki.openstack.org/wiki/Designate
+.. _LBaaS V2: http://https://wiki.openstack.org/wiki/Neutron/LBaaS
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/erd-diagram.dot b/specs/mitaka/sysarch/erd-diagram.dot
new file mode 100644
index 0000000..02ae8a8
--- /dev/null
+++ b/specs/mitaka/sysarch/erd-diagram.dot
@@ -0,0 +1,91 @@
+digraph "models_diagram" {
+ graph[overlap=false, splines=true, fontname="sans-serif", fontsize=10 ]
+ node [ fontname="sans-serif"fontsize=10 ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+
+
+ "LB" [shape=record, label="{\
+ loadbalancers|
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ name :string\l\
+ description :string\l\
+ fqdn :string\l\
+ zone_name :string\l\
+ flavor :enum\l\
+ appliance_id :string\l\
+ pool_ids :uuid\l\
+ }"]
+
+ "Pools" [shape=record, label="{\
+ pools|\l\
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ name :string\l\
+ description :string\l\
+ }"]
+
+ "PoolMembers" [shape=record, label="{\
+ pool_members|\l\
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ pool_id :string\l\
+ name :string\l\
+ description :string\l\
+ type :enum\l\
+ }"]
+
+ "PoolMemberParameters" [shape=record, label="{\
+ pool_member_parameters|\l\
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ pool_member_id :string\l\
+ key :enum\l\
+ value :string\l\
+ }"]
+
+ "Monitors" [shape=record, label="{\
+ monitors|\l\
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ name :string\l\
+ description :string\l\
+ type :string\l\
+ target :string\l\
+ auth :bool\l\
+ }"]
+
+ "MonitorParameters" [shape=record, label="{\
+ monitor_parameters|\l\
+ id :uuid\l\
+ project_id :string\l\
+ domain_id :string\l\
+ monitor_id :uuid\l\
+ key :enum\l\
+ value :string\l\
+ }"]
+
+ "PoolsMonitor" [shape=record, label="{\
+ pools_monitors|\l\
+ pool_id :uuid\l\
+ monitor_id :uuid\l\
+ }"]
+
+
+ { rank=same; "LB", "Pools" }
+ { rank=same; "PoolsMonitor" "PoolMembers" }
+ { rank=same; "Monitors" "PoolMemberParameters" "MonitorParameters" }
+
+ "LB" -> "Pools" [arrowtail=odot, arrowhead=crow, dir=both]
+
+ "Pools" -> "PoolsMonitor" [arrowtail=odot, arrowhead=crow, dir=both]
+ "PoolsMonitor" -> "Monitors" [arrowtail=crow, arrowhead=odot, dir=both]
+ "Monitors" -> "MonitorParameters" [arrowtail=odot, arrowhead=crow, dir=both]
+ "Pools" -> "PoolMembers" [arrowtail=odot, arrowhead=crow, dir=both]
+ "PoolMembers" -> "PoolMemberParameters" [arrowtail=odot, arrowhead=crow, dir=both]
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/example-flow.diag b/specs/mitaka/sysarch/example-flow.diag
new file mode 100644
index 0000000..36e719f
--- /dev/null
+++ b/specs/mitaka/sysarch/example-flow.diag
@@ -0,0 +1,19 @@
+seqdiag {
+
+ "End User";
+ Engine -> Conductor [label = "Get Load Balancer Information"];
+ Engine <-- Conductor;
+
+ Engine -> "Status Check" [label = "Tell Status Check to do a healthcheck"];
+ "Status Check" -> "Neutron LBaaS API" [label = "Get the Regional information from LBaaS V2 Status API"];
+ "Status Check" <-- "Neutron LBaaS API";
+ "Engine" <-- "Status Check";
+
+ Engine -> "Designate API" [label = "Tell Designate about what IPs to send traffic to"]
+ "Designate API" -> "DNS Servers" [label = "Designate updates DNS Server"]
+ "Designate API" <--"DNS Servers"
+ Engine <-- "Designate API"
+
+ "End User" -> "DNS Servers" [label = "User asks for IPs of Service"]
+ "End User" <-- "DNS Servers" [label = "DNS Returns IPs for the LBaaS VIPs of currently available regions"]
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/sysarch-diagram-conductor.dot b/specs/mitaka/sysarch/sysarch-diagram-conductor.dot
new file mode 100644
index 0000000..01cc304
--- /dev/null
+++ b/specs/mitaka/sysarch/sysarch-diagram-conductor.dot
@@ -0,0 +1,34 @@
+digraph "Kosmos"{
+ rankdir=TB
+ node [ fontname="sans-serif"fontsize=10 ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+ label="kosmos-conductor";
+ overlap="ortho";
+ fontname="sans-serif"
+ newrank=true
+
+ subgraph cluster_conductor_service {
+ fontname="sans-serif"
+ label="kosmos-conductor";
+ fontsize=12
+
+ Conductor[label="Conductor"];
+ Database[label="Database", shape="folder"];
+ Logger[label="Logger", shape="folder"];
+ }
+
+ { rank=same; "Conductor" "Engine" "WSGI" }
+
+ WSGI [style="invisible"]
+ Engine [style="invisible"]
+
+ WSGI -> Conductor [label="kosmos-api"];
+
+ Conductor -> Database [dir="both"];
+ Conductor -> Logger [dir="both"];
+
+ Conductor -> Engine [label="kosmos-engine"];
+
+
+
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/sysarch-diagram-engine.dot b/specs/mitaka/sysarch/sysarch-diagram-engine.dot
new file mode 100644
index 0000000..5c02399
--- /dev/null
+++ b/specs/mitaka/sysarch/sysarch-diagram-engine.dot
@@ -0,0 +1,34 @@
+digraph "Kosmos"{
+ rankdir=TB
+ node [ fontname="sans-serif"fontsize=10 ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+ label="kosmos-engine";
+ overlap="ortho";
+ fontname="sans-serif"
+ newrank=true
+
+ Conductor [style="invisible"]
+
+ subgraph cluster_engine_service {
+ fontname="sans-serif"
+ label="kosmos-engine";
+ fontsize=12
+
+ node[shape=record];
+ Engine[label="<f0> Engine|<f1> GSLB Plugin Interface |<f2> Status Check Consumer"];
+ PluginDriver[label="GSLB Plugin Driver", shape="component"]
+ }
+
+
+ ApplicanceAPI [style="invisible"]
+ Worker [style="invisible"]
+
+ Engine:f0 -> Conductor [label="kosmos-conductor"];
+
+ Engine:f1 -> PluginDriver [dir="both"];
+ PluginDriver -> ApplicanceAPI [dir="both" label="GSLB Appliance API"];
+
+
+ Worker -> Engine:f2[label="kosmos-status-checker"];
+
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/sysarch-diagram-overview.dot b/specs/mitaka/sysarch/sysarch-diagram-overview.dot
new file mode 100644
index 0000000..db97016
--- /dev/null
+++ b/specs/mitaka/sysarch/sysarch-diagram-overview.dot
@@ -0,0 +1,67 @@
+digraph "Kosmos"{
+ node [ fontname="sans-serif"fontsize=10; shape=record ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+ label="Kosmos System Overview";
+ overlap="ortho";
+ fontname="sans-serif"
+ newrank=true
+
+
+ API_user [
+ label="API User"
+ style="dashed"
+ ]
+
+ cluster_keystone [
+ label="Keystone";
+ style="dashed"
+ ]
+
+ cluster_api_service [
+ label="kosmos-api";
+ ]
+
+ cluster_conductor_service [
+ label="kosmos-conductor";
+ ]
+
+ cluster_engine_service [
+ label="kosmos-engine";
+ ]
+
+ cluster_gslb_appliance [
+ label="GSLB Appliance";
+ style="dotted"
+ ]
+
+ cluster_status_checks [
+ label="kosmos-status-check";
+ ]
+
+ cluster_endpoints [
+ label="Endpoints";
+ style="dashed"
+ ]
+
+ end_user [
+ label="End User"
+ style="dashed"
+ ]
+
+ API_user -> cluster_api_service
+ cluster_api_service -> cluster_keystone
+ cluster_api_service -> cluster_conductor_service
+
+ { rank=same; "API_user" "cluster_api_service" "cluster_keystone" }
+
+ cluster_conductor_service -> cluster_engine_service
+ cluster_status_checks -> cluster_engine_service
+ cluster_status_checks -> cluster_endpoints
+ cluster_engine_service -> cluster_gslb_appliance
+
+ { rank=same; "cluster_engine_service" "cluster_gslb_appliance" "end_user"}
+ { rank=same; "cluster_endpoints"}
+ end_user -> cluster_gslb_appliance
+ end_user -> cluster_endpoints
+
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/sysarch-diagram-status-checker.dot b/specs/mitaka/sysarch/sysarch-diagram-status-checker.dot
new file mode 100644
index 0000000..ac2cf52
--- /dev/null
+++ b/specs/mitaka/sysarch/sysarch-diagram-status-checker.dot
@@ -0,0 +1,35 @@
+digraph "Kosmos"{
+ rankdir=TB
+ node [ fontname="sans-serif"fontsize=10 ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+ label="kosmos-status-checker";
+ overlap="ortho";
+ fontname="sans-serif"
+ newrank=true
+
+ subgraph cluster_status_checks {
+ fontname="sans-serif"
+ fontsize=12
+ label="kosmos-status-checker";
+
+ Worker[label="Status Checking Worker"];
+
+ node[shape=record];
+ Checks[label="<f0> Build In Checks Interface |<f1> GSLB Plugin Checks Interface"];
+
+ BuiltInChecks[label="Built In Status Checks"]
+ PluginChecks[label="Plugin Status Checks", shape="component"]
+ }
+
+ Endpoints [style="invisible"]
+ Engine [style="invisible"]
+
+ Worker -> Engine [label="kosmos-engine"];
+ Worker -> Checks [dir="both"];
+ Checks:f0 -> BuiltInChecks [dir="both"];
+ Checks:f1 -> PluginChecks [dir="both"];
+ BuiltInChecks -> Endpoints [dir="both" label="Endpoints"];
+ PluginChecks -> Endpoints [dir="both" label="Endpoints"];
+
+
+}
\ No newline at end of file
diff --git a/specs/mitaka/sysarch/sysarch-diagram.dot b/specs/mitaka/sysarch/sysarch-diagram.dot
new file mode 100644
index 0000000..9040fad
--- /dev/null
+++ b/specs/mitaka/sysarch/sysarch-diagram.dot
@@ -0,0 +1,114 @@
+digraph "Kosmos"{
+ rankdir=TB
+ node [ fontname="sans-serif"fontsize=10 ];
+ edge [ fontname="sans-serif"fontsize=10 ];
+ label="Kosmos System Overview";
+ overlap="ortho";
+ fontname="sans-serif"
+ newrank=true
+
+ subgraph cluster_keystone {
+ fontname="sans-serif"
+ label="Keystone";
+ fontsize=12
+ style="dashed"
+
+ Keystone[label="Keystone API", style="dotted"];
+ }
+
+ subgraph cluster_api_service {
+ fontname="sans-serif"
+ label="API Service";
+ fontsize=12
+
+ WSGI[label="WSGI API"];
+ }
+
+
+ subgraph cluster_conductor_service {
+ fontname="sans-serif"
+ label="Conductor Service";
+ fontsize=12
+
+ Conductor[label="Conductor"];
+ Database[label="Database", shape="folder"];
+ Logger[label="Logger", shape="folder"];
+ }
+
+ subgraph cluster_engine_service {
+ fontname="sans-serif"
+ label="Engine Service";
+ fontsize=12
+
+ node[shape=record];
+ Engine[label="<f0> Engine|<f1> GSLB Plugin Interface |<f2> Status Check Consumer"];
+ PluginDriver[label="GSLB Plugin Driver", shape="component"]
+ }
+
+ subgraph cluster_gslb_appliance {
+ fontname="sans-serif"
+ fontsize=12
+ label="GSLB Appliance";
+ style="dashed"
+
+ Applicance[label="GSLB Traffic Director", style="dotted"];
+ ApplicanceAPI[label="GSLB Appliance API", style="dotted"];
+ }
+
+ subgraph cluster_status_checks {
+ fontname="sans-serif"
+ fontsize=12
+ label="Status Check Service";
+
+ Worker[label="Status Checking Worker"];
+
+ node[shape=record];
+ Checks[label="<f0> Build In Checks Interface |<f1> GSLB Plugin Checks Interface"];
+
+ BuiltInChecks[label="Built In Status Checks"]
+ PluginChecks[label="Plugin Status Checks", shape="component"]
+ }
+
+ subgraph cluster_endpoints {
+ fontname="sans-serif"
+ fontsize=12
+ label="Endpoints";
+ style="dashed"
+
+ Endpoint1[label="Endpoint", style="dotted"];
+ Endpoint2[label="Endpoint", style="dotted"];
+ Endpoint3[label="Endpoint", style="dotted"];
+ LBaaSAPI[label="LBaaS Status API", style="dotted"];
+
+ }
+
+ AdminUser[label="GSLB User", style="dashed"];
+ AdminUser -> WSGI [dir="both"];
+
+ Keystone -> WSGI [dir="both"];
+
+ WSGI -> Conductor:f0 [dir="both"];
+
+ Conductor -> Database [dir="both"];
+
+ Engine:f0 -> Conductor [dir="both"];
+
+ Engine:f1 -> PluginDriver [dir="both"];
+ PluginDriver -> ApplicanceAPI [dir="both"];
+
+ Applicance -> ApplicanceAPI [dir="both"];
+
+ Worker -> Engine:f2;
+ Worker -> Checks [dir="both"];
+ Checks:f0 -> BuiltInChecks [dir="both"];
+ Checks:f1 -> PluginChecks [dir="both"];
+ BuiltInChecks -> {Endpoint1; Endpoint2; Endpoint3; LBaaSAPI} [dir="both"];
+ LBaaSAPI -> {Endpoint1; Endpoint2; Endpoint3}
+ PluginChecks -> {Endpoint1; Endpoint2; Endpoint3} [dir="both"];
+
+ EndUser[label="End User", style="dashed"];
+
+ EndUser -> Applicance
+ EndUser -> {Endpoint1; Endpoint2; Endpoint3}
+
+}
\ No newline at end of file