X-Git-Url: http://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Database%2FRRDtool%2FCreate.hs;fp=Database%2FRRDtool%2FCreate.hs;h=e0146c0170035054ba447e57799dac9e47e09867;hb=5cab7a6846cf5ad61df14def9c0e023840bb756b;hp=0000000000000000000000000000000000000000;hpb=2c2948fbfa1b730beafa2dc8a5c6c81de54f2920;p=hs-rrdtool.git diff --git a/Database/RRDtool/Create.hs b/Database/RRDtool/Create.hs new file mode 100644 index 0000000..e0146c0 --- /dev/null +++ b/Database/RRDtool/Create.hs @@ -0,0 +1,177 @@ +module Database.RRDtool.Create + ( DataSource(..) + , createRRD + + -- Data.HList + , (.*.) + , HNil(..) + + -- Database.RRDtool.Expression + , Constant(..) + , IsVarName(..) + , Variable(..) + , CommonUnaryOp(..) + , CommonBinaryOp(..) + , CommonTrinaryOp(..) + , CommonSetOp(..) + , TrendOp(..) + , VariableShiftPredictOp(..) + , FixedShiftPredictOp(..) + , CommonValue(..) + ) + where + +import Data.HList +import Data.Time.Clock +import Data.Time.Clock.POSIX +import Database.RRDtool.Expression + + +-- |A single RRD can accept input from several data sources (DS), for +-- example incoming and outgoing traffic on a specific communication +-- line. With the DS configuration option you must define some basic +-- properties of each data source you want to store in the RRD. +-- +-- /NOTE on COUNTER vs DERIVE/ +-- +-- by Don Baarda +-- +-- If you cannot tolerate ever mistaking the occasional counter reset +-- for a legitimate counter wrap, and would prefer \"Unknowns\" for +-- all legitimate counter wraps and resets, always use DERIVE with +-- @'dsMin' = 0@. Otherwise, using COUNTER with a suitable max will +-- return correct values for all legitimate counter wraps, mark some +-- counter resets as \"Unknown\", but can mistake some counter resets +-- for a legitimate counter wrap. +-- +-- For a 5 minute step and 32-bit counter, the probability of +-- mistaking a counter reset for a legitimate wrap is arguably about +-- 0.8% per 1Mbps of maximum bandwidth. Note that this equates to 80% +-- for 100Mbps interfaces, so for high bandwidth interfaces and a +-- 32bit counter, DERIVE with @'dsMin' = 0@ is probably preferable. If +-- you are using a 64bit counter, just about any max setting will +-- eliminate the possibility of mistaking a reset for a counter wrap. +data DataSource + = -- |GAUGE is for things like temperatures or number of people in + -- a room or the value of a RedHat share. + GAUGE { + -- |The name you will use to reference this particular data + -- source from an RRD. A ds-name must be 1 to 19 characters + -- long in the characters @[a-zA-Z0-9_]@. + dsName :: !String + -- |Defines the maximum number of seconds that may + -- pass between two updates of this data source before the + -- value of the data source is assumed to be @*UNKNOWN*@. + , dsHeartbeat :: !NominalDiffTime + -- |'dsMin' and 'dsMax' Define the expected range values for + -- data supplied by a data source. If 'dsMin' and\/or 'dsMax' + -- any value outside the defined range will be regarded as + -- @*UNKNOWN*@. If you do not know or care about 'dsMin' and + -- 'dsMax', set them to 'Nothing' for unknown. Note that + -- 'dsMin' and 'dsMax' always refer to the processed values of + -- the DS. For a traffic-'COUNTER' type DS this would be the + -- maximum and minimum data-rate expected from the device. + -- + -- If information on minimal\/maximal expected values is + -- available, always set the min and\/or max properties. This + -- will help RRDtool in doing a simple sanity check on the + -- data supplied when running update. + , dsMin :: !(Maybe Double) + -- |See 'dsMin'. + , dsMax :: !(Maybe Double) + } + -- |COUNTER is for continuous incrementing counters like the + -- ifInOctets counter in a router. The COUNTER data source assumes + -- that the counter never decreases, except when a counter + -- overflows. The update function takes the overflow into + -- account. The counter is stored as a per-second rate. When the + -- counter overflows, RRDtool checks if the overflow happened at + -- the 32bit or 64bit border and acts accordingly by adding an + -- appropriate value to the result. + | COUNTER { + dsName :: !String + , dsHeartbeat :: !NominalDiffTime + , dsMin :: !(Maybe Double) + , dsMax :: !(Maybe Double) + } + -- |DERIVE will store the derivative of the line going from the + -- last to the current value of the data source. This can be + -- useful for gauges, for example, to measure the rate of people + -- entering or leaving a room. Internally, derive works exactly + -- like COUNTER but without overflow checks. So if your counter + -- does not reset at 32 or 64 bit you might want to use DERIVE and + -- combine it with a 'dsMin' value of 0. + | DERIVE { + dsName :: !String + , dsHeartbeat :: !NominalDiffTime + , dsMin :: !(Maybe Double) + , dsMax :: !(Maybe Double) + } + -- |ABSOLUTE is for counters which get reset upon reading. This is + -- used for fast counters which tend to overflow. So instead of + -- reading them normally you reset them after every read to make + -- sure you have a maximum time available before the next + -- overflow. Another usage is for things you count like number of + -- messages since the last update. + | ABSOLUTE { + dsName :: !String + , dsHeartbeat :: !NominalDiffTime + , dsMin :: !(Maybe Double) + , dsMax :: !(Maybe Double) + } + -- |COMPUTE is for storing the result of a formula applied to + -- other data sources in the RRD. This data source is not supplied + -- a value on update, but rather its Primary Data Points (PDPs) + -- are computed from the PDPs of the data sources according to the + -- rpn-expression that defines the formula. Consolidation + -- functions are then applied normally to the PDPs of the COMPUTE + -- data source (that is the rpn-expression is only applied to + -- generate PDPs). In database software, such data sets are + -- referred to as \"virtual\" or \"computed\" columns. + -- + -- FIXME: doc links + | forall a. IsCommonExpr a => COMPUTE { + dsName :: !String + -- |rpn-expression defines the formula used to compute the + -- PDPs of a COMPUTE data source from other data sources in + -- the same \. It is similar to defining a CDEF argument + -- for the graph command. For COMPUTE data sources, the + -- following RPN operations are not supported: COUNT, PREV, + -- TIME, and LTIME. In addition, in defining the RPN + -- expression, the COMPUTE data source may only refer to the + -- names of data source listed previously in the create + -- command. This is similar to the restriction that CDEFs must + -- refer only to DEFs and CDEFs previously defined in the same + -- graph command. + -- + -- FIXME: doc links + , dsExpr :: !a + } + +dsTest :: DataSource +dsTest = COMPUTE { + dsName = "foo" +-- , dsExpr = Previous :<: Const 100 +-- , dsExpr = Var "foo" :<: Const 100 + , dsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil) + } + +-- |The 'createRRD' function lets you set up new Round Robin Database +-- (RRD) files. The file is created at its final, full size and filled +-- with @*UNKNOWN*@ data. +createRRD + :: FilePath -- ^The name of the RRD you want to create. RRD files + -- should end with the extension @.rrd@. However, + -- RRDtool will accept any filename. + -> Bool -- ^Do not clobber an existing file of the same name. + -> Maybe POSIXTime -- ^Specifies the time in seconds since + -- @1970-01-01 UTC@ when the first value should + -- be added to the RRD. RRDtool will not accept + -- any data timed before or at the time + -- specified. (default: @now - 10s@) + -> Maybe NominalDiffTime -- ^Specifies the base interval in + -- seconds with which data will be fed + -- into the RRD. (default: 300 sec) + -> [DataSource] -- ^Data sources to accept input from. + -> IO () +createRRD = error "FIXME"