wip

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/ExponentialBackoff.kt

@@ -2,12 +2,14 @@ package com.birdthedeveloper.prometheus.android.prometheus.android.exporter.work
 
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.delay
+import kotlin.math.min
 import kotlin.math.pow
 
 class ExponentialBackoff {
     companion object {
         private const val multiplier: Double = 2.0
         private const val initialDelay = 3.0 // seconds
+        private const val maxDelay = 61.0 // seconds
 
         suspend fun runWithBackoff(function: suspend () -> Unit, onException: () -> Unit) {
             var successfull: Boolean = false
@@ -34,6 +36,7 @@ class ExponentialBackoff {
                     // calculate new delay
                     currentExpIndex++
                     currentDelay = initialDelay + multiplier.pow(currentExpIndex)
+                    currentDelay = min(currentDelay, maxDelay)
                 }
 
                 delay(currentDelay.toLong())

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/PromWorker.kt

@@ -12,8 +12,11 @@ import com.birdthedeveloper.prometheus.android.prometheus.android.exporter.R
 import com.birdthedeveloper.prometheus.android.prometheus.android.exporter.compose.PromConfiguration
 import io.prometheus.client.CollectorRegistry
 import io.prometheus.client.exporter.common.TextFormat
+import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.newSingleThreadContext
+import kotlinx.coroutines.withContext
 import java.io.StringWriter
 
 private const val TAG = "Worker"
@@ -45,19 +48,23 @@ class PromWorker(
         androidCustomExporter = AndroidCustomExporter(metricsEngine).register(collectorRegistry)
     }
 
-    private fun countSuccessfulScrape(){
+    private suspend fun countSuccessfulScrape(){
         remoteWriteSender?.countSuccessfulScrape()
     }
 
-    private suspend fun startServices(config: PromConfiguration) {
+    @OptIn(DelicateCoroutinesApi::class)
+    private suspend fun startServicesInOneThread(config: PromConfiguration){
+        val threadContext = newSingleThreadContext("PromWorkerThreadContext")
+
         var deferred = coroutineScope {
+            withContext(threadContext){
 
                 if (config.remoteWriteEnabled) {
                     remoteWriteSender = RemoteWriteSender(
                         RemoteWriteConfiguration(
                             config.remoteWriteScrapeInterval,
                             config.remoteWriteEndpoint,
-                        ::performScrape,
+                            collectorRegistry,
                         )
                     )
                     launch {
@@ -91,9 +98,7 @@ class PromWorker(
                         pushProxClient.start()
                     }
                 }
-
+            }
-
-
         }
     }
 
@@ -104,7 +109,7 @@ class PromWorker(
         //setForeground(createForegroundInfo())
 
         initializeWork(inputConfiguration)
-        startServices(inputConfiguration)
+        startServicesInOneThread(inputConfiguration)
 
         return Result.success()
     }

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/PrometheusServer.kt

@@ -21,7 +21,7 @@ private const val TAG = "PROMETHEUS_SERVER"
 data class PrometheusServerConfig(
     val port: Int,
     val performScrape: suspend () -> String,
-    val countSuccessfulScrape: () -> Unit,
+    val countSuccessfulScrape: suspend () -> Unit,
 )
 
 

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/PushProxClient.kt

@@ -21,7 +21,7 @@ data class PushProxConfig(
     val pushProxFqdn: String,
     val registry: CollectorRegistry,
     val performScrape: () -> String,
-    val countSuccessfulScrape: () -> Unit,
+    val countSuccessfulScrape: suspend () -> Unit,
 )
 
 /**

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/RemoteWriteSender.kt

@@ -8,58 +8,54 @@ import io.ktor.client.request.headers
 import io.ktor.client.request.post
 import io.ktor.client.request.setBody
 import io.ktor.http.HttpHeaders
+import io.prometheus.client.CollectorRegistry
+import kotlinx.coroutines.NonCancellable
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
 import org.iq80.snappy.Snappy
 import remote.write.RemoteWrite
 import remote.write.RemoteWrite.Label
 import remote.write.RemoteWrite.TimeSeries
 import remote.write.RemoteWrite.WriteRequest
-import java.util.Timer
-import kotlin.concurrent.schedule
 
 private const val TAG: String = "REMOTE_WRITE_SENDER"
 
-private class LastTimeMutex{
-    private val mutex = Mutex()
-    private var lastTime : Long = 0
-    suspend fun setLastTime(time : Long){
-        mutex.withLock {
-            lastTime = time
-        }
-    }
-    fun getLastTime() : Long { return lastTime }
-}
-
 private enum class RemoteWriteSenderState {
     REMOTE_WRITE,
     PUSHPROX_OR_PROMETHEUS_SERVER,
 }
 
-private class RemoteWriteSenderStateMutex {
+private class LastTimeRingBuffer {
-    private val mutex = Mutex()
+    //TODO implement this with ring array
-    private var remoteWriteSenderState = RemoteWriteSenderState.PUSHPROX_OR_PROMETHEUS_SERVER
+
-    suspend fun setRemoteWriteSenderState(state : RemoteWriteSenderState){
+    private fun checkScrapeDidNotHappenInTime() : Boolean {
-        mutex.withLock {
+        return lastTimeMutex.getLastTime() < System.currentTimeMillis() - 3 * config.scrape_interval
-            remoteWriteSenderState = state
-        }
     }
 
-    fun getRemoteWriteSenderState() : RemoteWriteSenderState {
+    private fun checkScrapeDidNotHappenHysteresis() : Boolean {
-        return remoteWriteSenderState
+        return false //TODO implement this with ring buffer in lastTimeMutex
     }
+
 }
 
 data class RemoteWriteConfiguration(
     val scrape_interval: Int,
     val remote_write_endpoint: String,
-    val performScrape: () -> String, //TODO this class needs it structured in objects
+    val collectorRegistry: CollectorRegistry,
 )
 
-//TODO implement this thing
 class RemoteWriteSender(private val config: RemoteWriteConfiguration) {
-    private val lastTimeMutex = LastTimeMutex()
+    // TODO ring buffer for last time
+    // TODO last time into it's own object with boolean functions
+    // private val lastTimeMutex = LastTimeMutex()
+    private var alreadyStoredSampleLength : Int = 0
+    private val storage : RemoteWriteSenderStorage = RemoteWriteSenderMemoryStorage()
+    private val scrapesAreBeingSentMutex = Mutex()
 
     private fun getRequestBody(): ByteArray {
         val label1: Label = Label.newBuilder()
@@ -104,25 +100,112 @@ class RemoteWriteSender(private val config: RemoteWriteConfiguration) {
         return request.toByteArray()
     }
 
-    suspend fun start(){
+    private fun performScrape() : MetricsScrape {
+
+
+        for ( item in config.collectorRegistry.metricFamilySamples() ){
+            val name : String = item.name
+            for (sample in item.samples){
+                val timestamp : Long = sample.timestampMs
+
+                val labelValueIterator : Iterator<String> = sample.labelValues.iterator()
+                for(labelName in sample.labelNames){
+                    val protobufLabel : Label = Label.newBuilder()
+                        .setName(labelName)
+                        .setValue(labelValueIterator.next())
+                        .build()
+                }
+
+                val sampleValue : Double = sample.value
+
+
+            }
+        }
+    }
+
+    //TODO channel je k hovnu
+    //TODO v remotewriteseender storage musi byt mutex
+
+
+    private suspend fun scraper(channel : Channel<Unit>){
+        val checkDelay = 1000L
+        while (true){
+            if (checkScrapeDidNotHappenInTime()){
+                delay(config.scrape_interval * 1000L)
+                storage.writeScrapedSample(performScrape())
+
+                while(checkScrapeDidNotHappenHysteresis()){
+                    delay(config.scrape_interval * 1000L)
+                    storage.writeScrapedSample(performScrape())
+                }
+            }
+            delay(checkDelay)
+        }
+    }
+
+    // sending metric scrapes to remote write endpoint will not be parallel
+    private suspend fun sendAll(){
+        scrapesAreBeingSentMutex.withLock {
+            // Take all metric samples and send them in batches of (max_samples_per_send)
+            // one by one batch
+
+
+        }
+    }
+
+    private suspend fun senderManager(channel : Channel<Unit>){
+        val alreadyStoredMetricScrapes : Int = storage.getLength()
+
         runBlocking {
-            //TODO from here
+            if (alreadyStoredMetricScrapes > 0){
+                launch { // fire and forget
+                    sendAll()
+                }
+            }
+
+            channel.receive()
+
+
+            // suspended on channel.receive
+
+            // when there are enough to send:
+            // start a sender
+
+            // send with these conditions:
+            //
         }
 
     }
 
-    fun countSuccessfulScrape(){
+    suspend fun start(){
-        Log.v(TAG, "countSuccesful scrape")
+       val channel = Channel<Unit>()
-        //TODO implement this "last time" and mutex
+       try {
+           runBlocking {
+               launch {
+                   scraper(channel)
+               }
+               launch {
+                   senderManager(channel)
+               }
+           }
+       } finally {
+           withContext(NonCancellable){
+               channel.close()
+               Log.v(TAG, "Canceling Remote Write Sender")
+           }
+       }
+    }
 
-        scheduleCheckScrapesHappened()
+    suspend fun countSuccessfulScrape(){
+        Log.v(TAG, "Counting successful scrape")
+        lastTimeMutex.setLastTime(System.currentTimeMillis())
     }
 
     private fun encodeWithSnappy(data: ByteArray): ByteArray {
         return Snappy.compress(data)
     }
 
-    suspend fun sendTestRequest() {
+    private suspend fun sendTestRequest() {
         Log.v(TAG, "sending to prometheus now")
         val client = HttpClient()
         val response = client.post(config.remote_write_endpoint) {
@@ -141,4 +224,3 @@ class RemoteWriteSender(private val config: RemoteWriteConfiguration) {
         client.close()
     }
 }
-

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/RemoteWriteSenderStorage.kt

@@ -1,16 +1,29 @@
 package com.birdthedeveloper.prometheus.android.prometheus.android.exporter.worker
 
-typealias MetricsScrape = String
+import java.sql.Timestamp
+import java.util.LinkedList
+import java.util.Queue
 
-// define the contract for Remote Write Sender storage
+//TODO toto je na houby cele, musi byt structured misto byte array
+class MetricsScrape(
+    val compressedMetrics : ByteArray,
+    val timestamp: Long,
+)
+
+// No need for locks as all operations are run on a single thread, defined in PromWorker
+// This class defines contract for RemoteWriteSender storage
 abstract class RemoteWriteSenderStorage {
     abstract fun writeScrapedSample(metricsScrape: MetricsScrape)
     abstract fun getNumberOfScrapedSamples(number: Int): List<MetricsScrape>
     abstract fun removeNumberOfScrapedSamples(number: Int)
     abstract fun isEmpty(): Boolean
+    abstract fun getLength(): Int
 }
 
 class RemoteWriteSenderMemoryStorage : RemoteWriteSenderStorage() {
+    // writeRequests are stored in protobuf already compressed
+    private val data : Queue<MetricsScrape> = LinkedList<MetricsScrape>()
+
     override fun getNumberOfScrapedSamples(number: Int): List<MetricsScrape> {
         TODO("Not yet implemented")
     }
@@ -26,6 +39,10 @@ class RemoteWriteSenderMemoryStorage : RemoteWriteSenderStorage() {
     override fun isEmpty(): Boolean {
         TODO("Not yet implemented")
     }
+
+    override fun getLength(): Int {
+        TODO("Not yet implemented")
+    }
 }
 
 class RemoteWriteSenterDatabaseStorage : RemoteWriteSenderStorage() {
@@ -44,4 +61,8 @@ class RemoteWriteSenterDatabaseStorage : RemoteWriteSenderStorage() {
     override fun isEmpty(): Boolean {
         TODO("Not yet implemented")
     }
+
+    override fun getLength(): Int {
+        TODO("Not yet implemented")
+    }
 }

config_file_structure.yaml

@@ -32,3 +32,6 @@ remote_write:
   # data type: string, no default value provided
   # example: http://localhost:9090/
   remote_write_endpoint:
+
+  # default value is 5 scrapes 
+  max_samples_per_send: 5