9 {-# LANGUAGE QuasiQuotes #-} -- DELETE THIS
10 module Database.RRDtool.Create
13 , ExternalDataSource(..)
14 , ComputedDataSource(..)
21 -- Database.RRDtool.Expression
30 , VariableShiftPredictOp(..)
31 , FixedShiftPredictOp(..)
37 import Data.Time.Clock
38 import Data.Time.Clock.POSIX
39 import Database.RRDtool.Expression
40 import Types.Data.Bool
43 -- |A single RRD can accept input from several data sources (DS), for
44 -- example incoming and outgoing traffic on a specific communication
45 -- line. With the DS configuration option you must define some basic
46 -- properties of each data source you want to store in the RRD.
48 -- /NOTE on COUNTER vs DERIVE/
50 -- by Don Baarda <don.baarda@baesystems.com>
52 -- If you cannot tolerate ever mistaking the occasional counter reset
53 -- for a legitimate counter wrap, and would prefer \"Unknowns\" for
54 -- all legitimate counter wraps and resets, always use DERIVE with
55 -- @'dsMin' = 0@. Otherwise, using COUNTER with a suitable max will
56 -- return correct values for all legitimate counter wraps, mark some
57 -- counter resets as \"Unknown\", but can mistake some counter resets
58 -- for a legitimate counter wrap.
60 -- For a 5 minute step and 32-bit counter, the probability of
61 -- mistaking a counter reset for a legitimate wrap is arguably about
62 -- 0.8% per 1Mbps of maximum bandwidth. Note that this equates to 80%
63 -- for 100Mbps interfaces, so for high bandwidth interfaces and a
64 -- 32bit counter, DERIVE with @'dsMin' = 0@ is probably preferable. If
65 -- you are using a 64bit counter, just about any max setting will
66 -- eliminate the possibility of mistaking a reset for a counter wrap.
70 = GAUGE -- ^GAUGE is for things like temperatures or number of
71 -- people in a room or the value of a RedHat share.
72 | COUNTER -- ^COUNTER is for continuous incrementing counters
73 -- like the ifInOctets counter in a router. The COUNTER
74 -- data source assumes that the counter never
75 -- decreases, except when a counter overflows. The
76 -- update function takes the overflow into account. The
77 -- counter is stored as a per-second rate. When the
78 -- counter overflows, RRDtool checks if the overflow
79 -- happened at the 32bit or 64bit border and acts
80 -- accordingly by adding an appropriate value to the
82 | DERIVE -- ^DERIVE will store the derivative of the line going
83 -- from the last to the current value of the data
84 -- source. This can be useful for gauges, for example,
85 -- to measure the rate of people entering or leaving a
86 -- room. Internally, derive works exactly like COUNTER
87 -- but without overflow checks. So if your counter does
88 -- not reset at 32 or 64 bit you might want to use
89 -- DERIVE and combine it with a 'dsMin' value of 0.
90 | ABSOLUTE -- ^ABSOLUTE is for counters which get reset upon
91 -- reading. This is used for fast counters which tend
92 -- to overflow. So instead of reading them normally you
93 -- reset them after every read to make sure you have a
94 -- maximum time available before the next
95 -- overflow. Another usage is for things you count like
96 -- number of messages since the last update.
97 deriving (Show, Eq, Ord)
99 data ExternalDataSource vn
100 = ExternalDataSource {
101 -- |The name you will use to reference this particular data
102 -- source from an RRD. A ds name must be 1 to 19 characters
103 -- long in the characters @[a-zA-Z0-9_]@.
105 -- |The type of this data source.
106 , edsType :: !ExternalDSType
107 -- |Defines the maximum number of seconds that may pass
108 -- between two updates of this data source before the value of
109 -- the data source is assumed to be @*UNKNOWN*@.
110 , edsHeartbeat :: !NominalDiffTime
111 -- |'edsMin' and 'edsMax' Define the expected range values for
112 -- data supplied by a data source. If 'edsMin' and\/or 'edsMax'
113 -- any value outside the defined range will be regarded as
114 -- @*UNKNOWN*@. If you do not know or care about 'edsMin' and
115 -- 'edsMax', set them to 'Nothing' for unknown. Note that
116 -- 'edsMin' and 'edsMax' always refer to the processed values of
117 -- the DS. For a traffic-'COUNTER' type DS this would be the
118 -- maximum and minimum data-rate expected from the device.
120 -- If information on minimal\/maximal expected values is
121 -- available, always set the min and\/or max properties. This
122 -- will help RRDtool in doing a simple sanity check on the
123 -- data supplied when running update.
124 , edsMin :: !(Maybe Double)
126 , edsMax :: !(Maybe Double)
128 deriving (Show, Eq, Ord)
130 instance ( IsVarName vn ~ True
132 => DataSource (ExternalDataSource vn)
135 -- |ComputedDataSource is for storing the result of a formula applied
136 -- to other data sources in the RRD. This data source is not supplied
137 -- a value on update, but rather its Primary Data Points (PDPs) are
138 -- computed from the PDPs of the data sources according to the
139 -- rpn-expression that defines the formula. Consolidation functions
140 -- are then applied normally to the PDPs of the COMPUTE data source
141 -- (that is the rpn-expression is only applied to generate PDPs). In
142 -- database software, such data sets are referred to as \"virtual\" or
143 -- \"computed\" columns.
146 data ComputedDataSource vn e
147 = ComputedDataSource {
150 -- |rpn-expression defines the formula used to compute the
151 -- PDPs of a COMPUTE data source from other data sources in
152 -- the same \<RRD\>. It is similar to defining a CDEF argument
153 -- for the graph command. For COMPUTE data sources, the
154 -- following RPN operations are not supported: COUNT, PREV,
155 -- TIME, and LTIME. In addition, in defining the RPN
156 -- expression, the COMPUTE data source may only refer to the
157 -- names of data source listed previously in the create
158 -- command. This is similar to the restriction that CDEFs must
159 -- refer only to DEFs and CDEFs previously defined in the same
165 deriving (Show, Eq, Ord)
167 instance ( IsVarName vn ~ True
168 , IsCommonExpr e ~ True
170 => DataSource (ComputedDataSource vn e)
173 dsTest = ComputedDataSource {
175 -- , cdsExpr = Previous :<: Const 100
176 -- , cdsExpr = Var "foo" :<: Const 100
177 , cdsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil)
181 -- |The name of the RRD you want to create. RRD files should end with
182 -- the extension @.rrd@. However, RRDtool will accept any filename.
183 newtype RRDPath = RRDPath FilePath
185 -- |Do not clobber an existing file of the same name.
186 data KeepOldRRD = KeepOldRRD
188 -- |Specifies the time in seconds since @1970-01-01 UTC@ when the
189 -- first value should be added to the RRD. RRDtool will not accept any
190 -- data timed before or at the time specified. (default: @now - 10s@)
191 newtype RRDStartTime = RRDStartTime POSIXTime
193 -- |Specifies the base interval in seconds with which data will be fed
194 -- into the RRD. (default: 300 sec)
195 newtype RRDInterval = RRDInterval NominalDiffTime
198 instance ( HOccurs RRDPath s
199 , HOccursOpt KeepOldRRD s
200 , HOccursOpt RRDStartTime s
201 , HOccursOpt RRDInterval s
205 class NonEmptyDSList l
209 => NonEmptyDSList (HCons ds l)
216 => DSList (HCons ds l)
218 -- DataList would be a graph...
220 -- |The 'createRRD' function lets you set up new Round Robin Database
221 -- (RRD) files. The file is created at its final, full size and filled
222 -- with @*UNKNOWN*@ data.
223 createRRD :: ( RRDSpec s
227 createRRD = error "FIXME"
230 testMain = let s = RRDPath "test.rrd" .&.
233 x = ComputedDataSource {
234 cdsName = [$hString|foo|]
235 , cdsExpr = Const 100