From 78dc26953868eb1ab5f5abc64dc13f935a2a1a05 Mon Sep 17 00:00:00 2001
From: Henry Dollman <hank@henrygd.me>
Date: Tue, 23 Jul 2024 15:47:15 -0400
Subject: [PATCH] update logic for batch updating servers

---
 hub/main.go | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/hub/main.go b/hub/main.go
index 5f41edb..ece9d63 100644
--- a/hub/main.go
+++ b/hub/main.go
@@ -15,16 +15,17 @@ import (
 	"net/url"
 	"os"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/labstack/echo/v5"
-	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase"
 	"github.com/pocketbase/pocketbase/apis"
 	"github.com/pocketbase/pocketbase/core"
 	"github.com/pocketbase/pocketbase/models"
 	"github.com/pocketbase/pocketbase/plugins/migratecmd"
 	"github.com/pocketbase/pocketbase/tools/cron"
+	"github.com/pocketbase/pocketbase/tools/types"
 	"github.com/spf13/cobra"
 	"golang.org/x/crypto/ssh"
 )
@@ -32,7 +33,8 @@ import (
 var Version = "0.0.1-alpha.6"
 
 var app *pocketbase.PocketBase
-var serverConnections = make(map[string]Server)
+var serverConnections = make(map[string]*Server)
+var serverConnectionsLock = sync.Mutex{}
 
 func main() {
 	app = pocketbase.NewWithConfig(pocketbase.Config{
@@ -207,49 +209,53 @@ func startSystemUpdateTicker() {
 }
 
 func updateSystems() {
-	// handle max of 1/3 + 1 servers at a time
-	numServers := len(serverConnections)/3 + 1
-	// find systems that are not paused and updated more than 58 seconds ago
-	fiftyEightSecondsAgo := time.Now().UTC().Add(-58 * time.Second).Format("2006-01-02 15:04:05")
 	records, err := app.Dao().FindRecordsByFilter(
-		"2hz5ncl8tizk5nx", // collection
-		"status != 'paused' && updated < {:updated}", // filter
-		"updated",  // sort
-		numServers, // limit
-		0,          // offset
-		dbx.Params{"updated": fiftyEightSecondsAgo},
+		"2hz5ncl8tizk5nx",    // collection
+		"status != 'paused'", // filter
+		"updated",            // sort
+		-1,                   // limit
+		0,                    // offset
 	)
+	// log.Println("records", len(records))
 	if err != nil {
 		app.Logger().Error("Failed to query systems: ", "err", err.Error())
 		return
 	}
-	for _, record := range records {
-		updateSystem(record)
+	fiftyFiveSecondsAgo := time.Now().UTC().Add(-55 * time.Second)
+	batchSize := len(records)/4 + 1
+	for i := 0; i < batchSize; i++ {
+		if records[i].Get("updated").(types.DateTime).Time().After(fiftyFiveSecondsAgo) {
+			break
+		}
+		// log.Println("updating", records[i].Get(("name")))
+		go updateSystem(records[i])
 	}
 }
 
 func updateSystem(record *models.Record) {
-	var server Server
+	var server *Server
 	// check if server connection data exists
 	if _, ok := serverConnections[record.Id]; ok {
 		server = serverConnections[record.Id]
 	} else {
 		// create server connection struct
-		server = Server{
+		server = &Server{
 			Host: record.Get("host").(string),
 			Port: record.Get("port").(string),
 		}
-		client, err := getServerConnection(&server)
+		client, err := getServerConnection(server)
 		if err != nil {
 			app.Logger().Error("Failed to connect:", "err", err.Error(), "server", server.Host, "port", server.Port)
 			updateServerStatus(record, "down")
 			return
 		}
 		server.Client = client
+		serverConnectionsLock.Lock()
 		serverConnections[record.Id] = server
+		serverConnectionsLock.Unlock()
 	}
 	// get server stats from agent
-	systemData, err := requestJson(&server)
+	systemData, err := requestJson(server)
 	if err != nil {
 		if err.Error() == "retry" {
 			// if previous connection was closed, try again
@@ -310,6 +316,8 @@ func deleteServerConnection(record *models.Record) {
 		if serverConnections[record.Id].Client != nil {
 			serverConnections[record.Id].Client.Close()
 		}
+		serverConnectionsLock.Lock()
+		defer serverConnectionsLock.Unlock()
 		delete(serverConnections, record.Id)
 	}
 }