adds lua version

README.md

@@ -1,24 +1,35 @@
-Boundary Memcached Plugin
--------------------------
+# Boundary Memcached Plugin
 
 Collects metrics from a memcached instance. See video [walkthrough](https://help.boundary.com/hc/articles/201816101).
 
-### Prerequisites
+## Prerequisites
+
+### Supported OS
 
 |     OS    | Linux | Windows | SmartOS | OS X |
 |:----------|:-----:|:-------:|:-------:|:----:|
 | Supported |   v   |    v    |    v    |  v   |
 
+#### Boundary Meter Versions V4.0 Or Later
+
+- To install new meter go to Settings->Installation or [see instructons|https://help.boundary.com/hc/en-us/sections/200634331-Installation]. 
+- To upgrade the meter to the latest version - [see instructons|https://help.boundary.com/hc/en-us/articles/201573102-Upgrading-the-Boundary-Meter].
+
+#### For Boundary Meter less than V4.0
+
 |  Runtime | node.js | Python | Java |
 |:---------|:-------:|:------:|:----:|
 | Required |    +    |        |      |
 
 - [How to install node.js?](https://help.boundary.com/hc/articles/202360701)
 
 ### Plugin Setup
+
 None
 
-#### Plugin Configuration Fields
+### Plugin Configuration Fields
+
+#### For All Versions
 
 |Field Name|Description                                                |
 |:---------|:----------------------------------------------------------|
@@ -27,6 +38,9 @@ None
 |Host      |The MEMCACHED hostname.                                    |
 
 ### Metrics Collected
+
+#### For All Versions
+
 |Metric Name          |Description                       |
 |:--------------------|:---------------------------------|
 |Memcached Allocated  |Percent of available memory used  |

init.lua

@@ -0,0 +1,105 @@
+local timer    = require('timer')
+local boundary = require('boundary')
+local io       = require('io')
+local net      = require('net')
+
+
+local __pgk        = "BOUNDARY MEMCACHED"
+local client
+local _previous    = {}
+local host         = "127.0.0.1"
+local port         = 11211
+local pollInterval = 1000
+
+
+if (boundary.param ~= nil) then
+  pollInterval = boundary.param.pollInterval or pollInterval
+  host          = boundary.param.host or host
+  port          = boundary.param.port or port
+  source             = (type(boundary.param.source) == 'string' and boundary.param.source:gsub('%s+', '') ~= '' and boundary.param.source) or
+   io.popen("uname -n"):read('*line')
+end
+
+
+function berror(err)
+  if err then print(string.format("%s ERROR: %s", __pgk, tostring(err))) return err end
+end
+
+
+
+function diff(a, b)
+    if a == nil or b == nil then return 0 end
+    return math.max(a - b, 0)
+end
+
+
+-- accumulate a value and return the difference from the previous value
+function accumulate(key, newValue)
+    local oldValue   = _previous[key] or newValue
+    local difference = diff(newValue, oldValue)
+    _previous[key]   = newValue
+    return difference
+end
+
+-- init client
+function init()
+  if client == nil then
+    client = net.createConnection(port, host, function (err)
+      if berror(err) then end
+    end)
+  end
+  client:on("error", function(err)
+      berror(err)
+  end)
+  client:on("data", function(data)
+
+      local d = {}
+      for _, v in pairs(split(data, "\r\n")) do
+        local s = v:gsub("STAT ", "")
+        local t = {}
+        for w in s:gmatch("%S+") do
+          table.insert(t, w)
+        end
+        d[t[1]] = tonumber(t[2])
+      end
+
+      print(string.format('MEMCACHED_ALLOCATED %d %s', d.bytes / d.limit_maxbytes, source))
+      print(string.format('MEMCACHED_CONNECTIONS %d %s', d.curr_connections, source))
+      print(string.format('MEMCACHED_HITS %d %s', accumulate('get_hits', d.get_hits), source))
+      print(string.format('MEMCACHED_MISSES %d %s', accumulate('get_misses', d.get_misses), source))
+      print(string.format('MEMCACHED_ITEMS %d %s', d.curr_items, source))
+      print(string.format('MEMCACHED_REQUESTS %d %s', accumulate('cmd_get', d.cmd_get) + accumulate('cmd_set', d.cmd_set), source))
+      print(string.format('MEMCACHED_NETWORK_IN %d %s', accumulate('bytes_read', d.bytes_read), source))
+      print(string.format('MEMCACHED_NETWORK_OUT %d %s', accumulate('bytes_written', d.bytes_written), source))
+  end)
+
+end
+
+
+-- get the natural difference between a and b
+function diff(a, b)
+  if not a or not b then return 0 end
+  return math.max(a - b, 0)
+end
+
+function split(str, delim)
+   local res = {}
+   local pattern = string.format("([^%s]+)%s()", delim, delim)
+   while (true) do
+      line, pos = str:match(pattern, pos)
+      if line == nil then break end
+      table.insert(res, line)
+   end
+   return res
+end
+
+print("_bevent:MEMCACHED plugin up : version 1.0|t:info|tags:memcached, lua, plugin")
+init()
+
+timer.setInterval(pollInterval, function ()
+  client:write("stats " .. "\r\n")
+end)
+
+
+
+