Dec 03, 2018  Hello, in this article I wanna share some experience of building a high available MySQL database cluster, from two master MySQL nodes, with load balancing and failover capability based on HAProxy & Heartbeat. PHP proxy and extensible web interface forwarding standard HKP requests to a local or remote SKS OpenPGP Keyserver. ctubio/php-proxy-keyserver.

1. Haproxy Node Is Unclean Number
2. Partition Without Quorum! Fencing And Resource Management Is Disabled.

node-haproxy

Set, modify and hot load haproxy configuration from node.

Functionality and code lifted and adapted fromthalassa=aqueduct.

You can run this module standalone (npm install -g node-haproxy; node-haproxy --ipc) andcommunicate with it using ipc (var ipcClient = require ('node-haproxy/src/ipc-client')or use the api directly (var haproxy = require('node-haproxy').

In both cases it will fire up a haproxy instance which you can query and modify programmatically.

When modifying or adding/removing front and backends programmatically haproxy isreconfigured on the fly. Back and frontends are persisted between restarts of the node process.

Changes are saved to a leveldb.

When no options are passed in, the included haproxy executable (v1.5) is used.The leveldb and persisted data is stored by default in the module's folder. Which meansthat on updating or reinstalling the module the data is wiped.

Locations of the leveldb, template haproxy.cfg file and persisted info file canbe set using options, amongst some more settings relating to haproxy.

Paraphrased from the original readme:

HAProxy Fundamentals

Node-haproxy does not try to obfuscate HAProxy, and it's important to know the fundamentals of how HAProxy works to understand node-haproxy. The API mirrors HAProxy's semantics. The HAProxy documentation contains a wealth of detailed information.

1. Frontends - A 'frontend' section describes a set of listening sockets accepting clientconnections.

2. Backends - A 'backend' section describes a set of servers to which the proxy will connectto forward incoming connections.

3. Members/Servers - node-haproxy calls the servers that backends route to 'members'. In other words, members of a backend pool of servers.

4. Config file - At startup, HAProxy loads a configuration file and never looks at that file again. node-haproxy manages this by re-templating a new config file and gracefully restarting the HAProxy process.

5. Stats Socket - a UNIX socket in stream mode that will return various statistics outputs and even allows some basic configuration tweaking like enabling and disabling existing backend members, setting weights, etc.

Options

The following functions can be invoked on the required node-haproxy module orusing the ipc-client (ipcClient(functionName, args), which uses promises:Don't forget to call ipcClient.close() if you want to stop the node process..

Example of using the ipc-client:

getFrontends()

Returns Array of frontend objects for all of the frontends configured

For example:

getFrontend(key)

Gets a specific frontend by key.

putFrontend(key, obj)

Create or update a frontend by key.

deleteFrontend(key)

Delete a specific frontend by key.

getBackends()

Returns Array of backend objects for all of the backends configured

For example:

getBackend(key)

Gets a specific backend by key.

putBackend(key, obj)

Haproxy Node Is Unclean Number

Create or update a backend by key.

deleteBackend(key)

Delete a specific backend by key.

updateBackend(key)

Update a backends role and version

name is actually optional. You may also just send the version:

getHaproxyConfig()

Partition Without Quorum! Fencing And Resource Management Is Disabled.

Return the last know generated HAProxy config file contents that were written to the location of opts.haproxyCfgPath.

Routing Rules

There are currently 3 types of rules that can be applied to frontends: path, url, and header.

Path rules support path, path_beg, and path_reg HAProxy operations

Url rules support url, url_beg, and url_reg HAProxy operations

Header rules support hdr_dom with a entire value at this point

Natives

The natives property is an end around way to insert raw lines of config for front ends and backends. Use them sparingly but use them if you need them.

TODO

• thrown exceptions are are not handled in api.js and dependencies
• remove health checks/roles/version leftover from Aqea