> ## Documentation Index > Fetch the complete documentation index at: https://ayakaleaf-pro.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Horisontal skalering > Kør flere Ayakaleaf Pro-replikaer bag en load balancer med sticky sessions. Én replika bruger én nodes CPU til hver kompilering: på vores testnoder med 2 vCPU'er tog seks samtidige kompileringer tre gange så lang tid som én, mens de andre noder stod ubrugte hen. Flere replikaer fordeler brugerne og deres kompileringer over noderne. Dette følger Overleafs design for [Horisontal skalering](https://ayakaleaf-pro.mintlify.site/da/on-premises/maintenance/horizontal-scaling.md), oversat til Kubernetes: | Krav | Her | | - | - | | Delt MongoDB og Redis | `10-mongo.yaml` og `20-redis.yaml` fra installationen | | Delte hemmeligheder | Secret'en `overleaf-secrets` fra [trin 2](https://ayakaleaf-pro.mintlify.site/da/on-premises/installation/using-kubernetes/2.-create-the-namespace-and-secrets.md) har dem allerede | | Projektfiler og historik i **S3** (ikke NFS) | enhver S3-tjeneste, se [S3](https://ayakaleaf-pro.mintlify.site/da/on-premises/configuration/kubernetes/s3.md); Garage dér som et eksempel i clusteret | | En lokal disk pr. replika til kompileringer og uploads | `hostPath` `/srv/overleaf-ha` på hver node | | Vedvarende routing, WebSockets, 10 min. timeouts, 50 MB uploads | HAProxy med Overleafs eksempelkonfiguration | | git-bridge som singleton ved siden af én replika | git-bridge med `overleaf-0` som søskende | > [!WARNING] > > Planlæg S3 fra starten. En instans, der allerede gemmer filer på sin volumen, kræver først [S3-migreringen](https://ayakaleaf-pro.mintlify.site/da/on-premises/maintenance/s3-migration.md). Denne opsætning erstatter Deployment'en fra trin 5: slet den (`kubectl delete -f 40-overleaf.yaml`), før du anvender StatefulSet'et. **1. S3-lager** Opsæt de tre buckets og to brugere som beskrevet i [S3](https://ayakaleaf-pro.mintlify.site/da/on-premises/configuration/kubernetes/s3.md) med din S3-tjeneste eller med Garage i clusteret, og læg de fire nøgler i Secret'en `overleaf-s3`. Konfigurationen nedenfor bruger Garage-eksemplet fra den side. **2. Konfiguration** Denne ConfigMap erstatter `30-config.yaml`. Den tilføjer S3 og git-bridge og peger `OVERLEAF_SITE_URL` på load balanceren: ```yaml title="60-config.yaml" wrap theme={null} apiVersion: v1 kind: ConfigMap metadata: name: overleaf-env namespace: overleaf data: OVERLEAF_APP_NAME: Ayakaleaf Pro OVERLEAF_SITE_URL: http://192.0.2.10:30081 # the load balancer (HAProxy) URL OVERLEAF_ADMIN_EMAIL: admin@example.com # Emails: add the sender and the SMTP server together, see Email delivery OVERLEAF_MONGO_URL: mongodb://mongo-0.mongo:27017,mongo-1.mongo:27017,mongo-2.mongo:27017/sharelatex?replicaSet=overleaf OVERLEAF_REDIS_HOST: redis REDIS_HOST: redis ENABLED_LINKED_FILE_TYPES: project_file,project_output_file,url ENABLE_CONVERSIONS: "true" EMAIL_CONFIRMATION_DISABLED: "true" OVERLEAF_TRUSTED_PROXY_IPS: loopback,10.244.0.0/16 # HAProxy runs in the pod CIDR # Sandboxed compiles, node paths: each replica owns /srv/overleaf-ha on its node SANDBOXED_COMPILES: "true" SANDBOXED_COMPILES_SIBLING_CONTAINERS: "true" DOCKER_RUNNER: "true" SANDBOXED_COMPILES_HOST_DIR_COMPILES: /srv/overleaf-ha/data/compiles SANDBOXED_COMPILES_HOST_DIR_OUTPUT: /srv/overleaf-ha/data/output SANDBOXED_COMPILES_HOST_DIR_CACHE: /srv/overleaf-ha/data/cache ALL_TEX_LIVE_DOCKER_IMAGES: ghcr.io/ayaka-notes/texlive-full:2026.1 ALL_TEX_LIVE_DOCKER_IMAGE_NAMES: TeX Live 2026 TEX_LIVE_DOCKER_IMAGE: ghcr.io/ayaka-notes/texlive-full:2026.1 # S3 (required for more than one replica); keys are in the Secret overleaf-s3 OVERLEAF_FILESTORE_BACKEND: s3 OVERLEAF_FILESTORE_TEMPLATE_FILES_BUCKET_NAME: overleaf-template-files OVERLEAF_FILESTORE_S3_ENDPOINT: http://garage:3900 OVERLEAF_FILESTORE_S3_PATH_STYLE: "true" OVERLEAF_FILESTORE_S3_REGION: garage OVERLEAF_HISTORY_BACKEND: s3 OVERLEAF_HISTORY_PROJECT_BLOBS_BUCKET: overleaf-project-blobs OVERLEAF_HISTORY_CHUNKS_BUCKET: overleaf-chunks OVERLEAF_HISTORY_S3_ENDPOINT: http://garage:3900 OVERLEAF_HISTORY_S3_PATH_STYLE: "true" OVERLEAF_HISTORY_S3_REGION: garage # Git integration: one git-bridge, its sibling is overleaf-0 GIT_BRIDGE_ENABLED: "true" GIT_BRIDGE_HOST: 10.96.100.80 # the git-bridge Service's fixed ClusterIP, see 75-git-bridge.yaml GIT_BRIDGE_PORT: "8000" ``` **3. Replikaer** ```yaml title="70-overleaf.yaml" wrap theme={null} apiVersion: v1 kind: Service metadata: name: overleaf-hl namespace: overleaf spec: clusterIP: None # stable DNS per replica: overleaf-0.overleaf-hl, ... selector: app: overleaf-ha ports: - {name: http, port: 80} - {name: web, port: 3000} # git-bridge API (sibling only) - {name: history, port: 3100} # history-v1, used by git-bridge via V1_HISTORY_URL --- apiVersion: apps/v1 kind: StatefulSet metadata: name: overleaf namespace: overleaf spec: serviceName: overleaf-hl replicas: 3 # OrderedReady: overleaf-0 runs the migrations alone before the next replica starts podManagementPolicy: OrderedReady selector: matchLabels: app: overleaf-ha template: metadata: labels: app: overleaf-ha spec: terminationGracePeriodSeconds: 60 # Keep the environment to the ConfigMap and Secrets: no REDIS_PORT=tcp://..., GIT_BRIDGE_PORT=tcp://... enableServiceLinks: false affinity: podAntiAffinity: # one replica per node: each uses that node's Docker and disk requiredDuringSchedulingIgnoredDuringExecution: - labelSelector: matchLabels: app: overleaf-ha topologyKey: kubernetes.io/hostname containers: - name: sharelatex image: ghcr.io/ayaka-notes/overleaf-pro:6.3.2 env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name # Each replica hands out history URLs with its own stable name, so git-bridge can reach them - name: V1_HISTORY_URL value: http://$(POD_NAME).overleaf-hl.overleaf.svc.cluster.local:3100/api envFrom: - configMapRef: {name: overleaf-env} - secretRef: {name: overleaf-secrets} - secretRef: {name: overleaf-s3} ports: - containerPort: 80 readinessProbe: httpGet: {path: /status, port: 80} periodSeconds: 10 resources: requests: {cpu: 500m, memory: 1536Mi} limits: {memory: 3Gi} volumeMounts: - {name: local, mountPath: /var/lib/overleaf} - {name: docker-sock, mountPath: /var/run/docker.sock} volumes: # Local disk for ephemeral files (compiles, output, uploads); the HOST_DIR_* paths are under it - name: local hostPath: {path: /srv/overleaf-ha, type: DirectoryOrCreate} - name: docker-sock hostPath: {path: /var/run/docker.sock, type: Socket} ``` * **StatefulSet, ikke Deployment.** Hver replika får et stabilt navn (`overleaf-0`, `overleaf-1`, ...), som load balancerens cookie og git-bridge henviser til, og `OrderedReady` starter først `overleaf-0` alene, så kun én replika kører databasemigreringerne. * **Én replika pr. node.** Hver replika starter sine kompileringer via sin nodes Docker og gemmer dem i sin nodes `/srv/overleaf-ha`. * **`V1_HISTORY_URL` pr. replika.** Hver replika udleverer historiklinks med sit eget navn, så git-bridge kan nå dem. **4. git-bridge** ```yaml title="75-git-bridge.yaml" wrap theme={null} apiVersion: v1 kind: Service metadata: name: git-bridge namespace: overleaf spec: # Fixed ClusterIP (inside the service CIDR): the sharelatex image's nginx proxies /git/ with # `resolver 127.0.0.11` (Docker's DNS), which does not exist in Kubernetes, so GIT_BRIDGE_HOST is this IP clusterIP: 10.96.100.80 selector: app: git-bridge ports: - {name: http, port: 8000} --- apiVersion: apps/v1 kind: StatefulSet metadata: name: git-bridge namespace: overleaf spec: serviceName: git-bridge replicas: 1 selector: matchLabels: app: git-bridge template: metadata: labels: app: git-bridge spec: # Service "git-bridge" would inject GIT_BRIDGE_PORT=tcp://..., which git-bridge reads as its port enableServiceLinks: false containers: - name: git-bridge image: ghcr.io/ayaka-notes/overleaf-pro/git-bridge:6.3.2 # same version as the sharelatex image command: ["/server-pro-start.sh"] securityContext: runAsUser: 0 env: - {name: GIT_BRIDGE_API_BASE_URL, value: "http://overleaf-0.overleaf-hl.overleaf.svc.cluster.local:3000/api/v0/"} - {name: GIT_BRIDGE_OAUTH2_SERVER, value: "http://overleaf-0.overleaf-hl.overleaf.svc.cluster.local"} - {name: GIT_BRIDGE_POSTBACK_BASE_URL, value: "http://git-bridge.overleaf.svc.cluster.local:8000"} - {name: GIT_BRIDGE_ROOT_DIR, value: /data/git-bridge} ports: - containerPort: 8000 resources: requests: {cpu: 100m, memory: 256Mi} limits: {memory: 768Mi} volumeMounts: - {name: data, mountPath: /data/git-bridge} volumeClaimTemplates: - metadata: name: data spec: accessModes: [ReadWriteOnce] resources: requests: storage: 5Gi ``` Se [Git-integration](https://ayakaleaf-pro.mintlify.site/da/on-premises/configuration/kubernetes/integrations/git-integration.md) for, hvorfor `GIT_BRIDGE_HOST` er en fast IP-adresse. **5. Load balancer** HAProxy-konfigurationen er Overleafs eksempel med fem ændringer: `/project//mcp` routes til `overleaf-0` ligesom `/git/` (se [MCP-server](https://ayakaleaf-pro.mintlify.site/da/on-premises/configuration/kubernetes/integrations/mcp-server.md#several-replicas)), almindelig HTTP på port `8080` (imaget kører som en ikke-root-bruger, der ikke kan binde port 80 under containerd), servere findes via cluster-DNS (pod-IP'er ændres ved hver genstart), et DaemonSet, så hver node svarer, og `balance leastconn` i stedet for standarden `roundrobin` (se spørgsmål og svar nedenfor). ```yaml title="80-haproxy.yaml" wrap theme={null} apiVersion: v1 kind: ConfigMap metadata: name: haproxy-config namespace: overleaf data: haproxy.cfg: | global log stdout format raw local0 info resolvers kubedns parse-resolv-conf hold valid 10s defaults mode http # New sessions go to the replica with the fewest open connections (editors keep a WebSocket open) balance leastconn option httpchk HEAD /status http-check expect status 200 default-server check resolvers kubedns init-addr none log global option httplog # Reroute to a different backend if the sticky one is down option redispatch 1 retries 3 # Sticky session for 24h of inactivity -- compile output is deleted after 24h cookie server-pro-ha insert maxidle 24h timeout queue 1m timeout connect 15s timeout client 1m # Allow slow compiles -- hard-coded limit in clsi is 10min timeout server 10m # Disconnect the editor after 23h timeout tunnel 23h # Lower than NGINX_KEEPALIVE_TIMEOUT (65s) in the sharelatex container timeout http-keep-alive 60s listen overleaf bind :8080 option forwardfor # When TLS ends in front of HAProxy, also pass: http-request set-header X-Forwarded-Proto https # git requests go to the git-bridge sibling use-server overleaf-0 if { path_beg /git/ } # MCP clients send no cookie: keep compile, log and PDF download on one replica use-server overleaf-0 if { path_reg ^/project/[0-9a-f]{24}/mcp(/|$) } http-response add-header X-Served-By %s stats enable stats uri /haproxy server overleaf-0 overleaf-0.overleaf-hl.overleaf.svc.cluster.local:80 cookie overleaf-0 server overleaf-1 overleaf-1.overleaf-hl.overleaf.svc.cluster.local:80 cookie overleaf-1 server overleaf-2 overleaf-2.overleaf-hl.overleaf.svc.cluster.local:80 cookie overleaf-2 --- apiVersion: apps/v1 # DaemonSet: one HAProxy per node, so the NodePort answers on every node with externalTrafficPolicy # Local. The cookie holds the replica name, so stickiness works whichever HAProxy a request hits. kind: DaemonSet metadata: name: haproxy namespace: overleaf spec: selector: matchLabels: app: haproxy template: metadata: labels: app: haproxy annotations: config-hash: "1" # bump to restart after editing the ConfigMap spec: containers: - name: haproxy image: haproxy:lts-alpine ports: - containerPort: 8080 resources: requests: {cpu: 50m, memory: 32Mi} limits: {memory: 256Mi} volumeMounts: - {name: config, mountPath: /usr/local/etc/haproxy} volumes: - name: config configMap: name: haproxy-config --- apiVersion: v1 kind: Service metadata: name: haproxy namespace: overleaf spec: type: NodePort externalTrafficPolicy: Local # keep the client IP (no SNAT); only nodes running HAProxy answer selector: app: haproxy ports: - {name: http, port: 80, targetPort: 8080, nodePort: 30081} ``` ```bash theme={null} kubectl delete -f 40-overleaf.yaml --ignore-not-found kubectl apply -f 60-config.yaml -f 70-overleaf.yaml -f 75-git-bridge.yaml -f 80-haproxy.yaml kubectl -n overleaf rollout status statefulset/overleaf --timeout=20m curl -sI http://192.0.2.10:30081/login | grep -i x-served-by ``` `externalTrafficPolicy: Local` bevarer brugernes IP-adresser i `X-Forwarded-For`. **6. TLS** Afslut HTTPS i HAProxy som beskrevet i [TLS-proxy](https://ayakaleaf-pro.mintlify.site/da/on-premises/configuration/kubernetes/tls-proxy.md), og sæt derefter `OVERLEAF_SITE_URL` til `https://`-adressen og `OVERLEAF_SECURE_COOKIE: "true"` i `60-config.yaml`. ### Hvad du kan forvente Vi testede tre replikaer på tre noder med hver 2 vCPU'er og 4 GB, med MongoDB, Redis, Garage, git-bridge og HAProxy på de samme noder: * 12 brugere, der kompilerede et dokument på 600 sider samtidig: alle 12 kompilerede og hentede deres PDF, 4 brugere pr. replika; en runde tog 8 til 18 sekunder. Hver node beholdt mindst 1,3 GB ledig hukommelse. * Hver bruger bliver på én replika (cookie `server-pro-ha`), herunder PDF-downloadet, der skal komme fra den replika, der kompilerede det. Det samme gælder over HTTPS, herunder editorens WebSocket. * Når en replika stopper, får dens brugere fejl i omkring 15 til 20 sekunder, indtil HAProxy markerer den som nede; derefter flyttes de til en anden replika og forbliver logget ind, fordi sessioner ligger i Redis. ### Spørgsmål og svar > [accordion] Hvorfor `balance leastconn`? > > **Svar:** Med Overleafs eksempel (`roundrobin`, én HAProxy pr. node) endte 12 nye brugere med at fordele sig med 8, 3 og 1 på de tre replikaer i vores test, og den travleste replika fik de langsomste brugere til at vente 29 sekunder. Med `leastconn`, der foretrækker replikaen med færrest åbne forbindelser (hver editor holder en WebSocket åben), gav den samme test 4, 4 og 4 og 18 sekunder. Stickiness er uændret: den kommer fra cookien. > [accordion] Kan jeg bruge min ingress-controller i stedet for HAProxy? > > **Svar:** Ja, hvis den router via en cookie til en stabil replika, understøtter WebSockets, tillader forespørgselstider på 10 minutter og uploads på 50 MB, holder sin keep-alive-timeout under 65 sekunder, sender `X-Forwarded-For` og `X-Forwarded-Proto` og sender `/git/` og `/project//mcp` til `overleaf-0`. Route til replikaernes egne navne (`overleaf-N.overleaf-hl`), ikke til en Service, der fordeler hver forespørgsel. > [accordion] Hvordan tilføjer jeg en fjerde replika? > > **Svar:** Tilføj en node med Docker og TeX Live-imagesene, sæt `replicas: 4` i `70-overleaf.yaml`, og tilføj en linje `server overleaf-3 ...` til HAProxy-konfigurationen (og forøg `config-hash`, så HAProxy genstarter). This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.