diagrams/docs/getting-started/examples.md

---
id: examples
title: Examples
---

Here are some more examples.

## Grouped Workers

```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
from diagrams.aws.database import RDS
from diagrams.aws.network import ELB

with Diagram("Grouped Workers", show=False, direction="TB"):
    ELB("lb") >> [EC2("worker1"),
                  EC2("worker2"),
                  EC2("worker3"),
                  EC2("worker4"),
                  EC2("worker5")] >> RDS("events")
```

![grouped workers diagram](/img/grouped_workers_diagram.png)

## Clustered Web Services

```python
from diagrams import Cluster, Diagram
from diagrams.aws.compute import ECS
from diagrams.aws.database import ElastiCache, RDS
from diagrams.aws.network import ELB
from diagrams.aws.network import Route53

with Diagram("Clustered Web Services", show=False):
    dns = Route53("dns")
    lb = ELB("lb")

    with Cluster("Services"):
        svc_group = [ECS("web1"),
                     ECS("web2"),
                     ECS("web3")]

    with Cluster("DB Cluster"):
        db_master = RDS("userdb")
        db_master - [RDS("userdb ro")]

    memcached = ElastiCache("memcached")

    dns >> lb >> svc_group
    svc_group >> db_master
    svc_group >> memcached
```

![clustered web services diagram](/img/clustered_web_services_diagram.png)

## Event Processing

```python
from diagrams import Cluster, Diagram
from diagrams.aws.compute import ECS, EKS, Lambda
from diagrams.aws.database import Redshift
from diagrams.aws.integration import SQS
from diagrams.aws.storage import S3

with Diagram("Event Processing", show=False):
    source = EKS("k8s source")

    with Cluster("Event Flows"):
        with Cluster("Event Workers"):
            workers = [ECS("worker1"),
                       ECS("worker2"),
                       ECS("worker3")]

        queue = SQS("event queue")

        with Cluster("Processing"):
            handlers = [Lambda("proc1"),
                        Lambda("proc2"),
                        Lambda("proc3")]

    store = S3("events store")
    dw = Redshift("analytics")

    source >> workers >> queue >> handlers
    handlers >> store
    handlers >> dw
```

![event processing diagram](/img/event_processing_diagram.png)

## Message Collecting System

```python
from diagrams import Cluster, Diagram
from diagrams.gcp.analytics import BigQuery, Dataflow, PubSub
from diagrams.gcp.compute import AppEngine, Functions
from diagrams.gcp.database import BigTable
from diagrams.gcp.iot import IotCore
from diagrams.gcp.storage import GCS

with Diagram("Message Collecting", show=False):
    pubsub = PubSub("pubsub")

    with Cluster("Source of Data"):
        [IotCore("core1"),
         IotCore("core2"),
         IotCore("core3")] >> pubsub

    with Cluster("Targets"):
        with Cluster("Data Flow"):
            flow = Dataflow("data flow")

        with Cluster("Data Lake"):
            flow >> [BigQuery("bq"),
                     GCS("storage")]

        with Cluster("Event Driven"):
            with Cluster("Processing"):
                flow >> AppEngine("engine") >> BigTable("bigtable")

            with Cluster("Serverless"):
                flow >> Functions("func") >> AppEngine("appengine")

    pubsub >> flow
```

![message collecting diagram](/img/message_collecting_diagram.png)

## Exposed Pod with 3 Replicas on k8s

```python
from diagrams import Diagram
from diagrams.k8s.clusterconfig import HPA
from diagrams.k8s.compute import Deployment, Pod, ReplicaSet
from diagrams.k8s.network import Ingress, Service

with Diagram("Exposed Pod with 3 Replicas", show=False):
    net = Ingress("domain.com") >> Service("svc")
    net >> [Pod("pod1"),
            Pod("pod2"),
            Pod("pod3")] << ReplicaSet("rs") << Deployment("dp") << HPA("hpa")

```

![exposed pod with 3 replicas diagram](/img/exposed_pod_with_3_replicas_diagram.png)

## Stateful Architecture on k8s

```python
from diagrams import Cluster, Diagram
from diagrams.k8s.compute import Pod, StatefulSet
from diagrams.k8s.network import Service
from diagrams.k8s.storage import PV, PVC, StorageClass

with Diagram("Stateful Architecture", show=False):
    with Cluster("Apps"):
        svc = Service("svc")
        sts = StatefulSet("sts")

        apps = []
        for _ in range(3):
            pod = Pod("pod")
            pvc = PVC("pvc")
            pod - sts - pvc
            apps.append(svc >> pod >> pvc)

    apps << PV("pv") << StorageClass("sc")
```

![stateful architecture diagram](/img/stateful_architecture_diagram.png)

## RabbitMQ Consumers with custom nodes

```python
from urllib.request import urlretrieve

from diagrams import Cluster, Diagram
from diagrams.custom import Custom
from diagrams.aws.database import Aurora
from diagrams.k8s.compute import Pod

# Download an image to be used into a Custom Node class
rabbitmq_url = "https://jpadilla.github.io/rabbitmqapp/assets/img/icon.png"
rabbitmq_icon = "rabbitmq.png"
urlretrieve(rabbitmq_url, rabbitmq_icon)


with Diagram("Broker Consumers", show=False):
    with Cluster("Consumers"):
        consumers = [
            Pod("worker"),
            Pod("worker"),
            Pod("worker")
        ]

    queue = Custom("Message queue", rabbitmq_icon)

    queue >> consumers >> Aurora("Database")
````

![rabbitmq consumers diagram](/img/rabbitmq_consumers_diagram.png)

## On-Premise System Architecture

```python
from diagrams import Cluster, Diagram
from diagrams.onprem.analytics import Spark
from diagrams.onprem.compute import Server
from diagrams.onprem.database import PostgreSQL
from diagrams.onprem.inmemory import Redis
from diagrams.onprem.logging import Fluentd
from diagrams.onprem.monitoring import Grafana, Prometheus
from diagrams.onprem.network import Linkerd, Nginx
from diagrams.onprem.queue import Kafka
from diagrams.onprem.workflow import Airflow

with Diagram("On-Premise System Architecture", show=False):
    ingress = Nginx("ingress")

    with Cluster("Service Cluster"):
        svcmesh = Linkerd("svcmesh")
        grpcsvc = [Server("grpc1"), Server("grpc2"), Server("grpc3")]
        svcmesh >> grpcsvc

    with Cluster("Database HA"):
        maindb_master = PostgreSQL("maindb")
        maindb_replica = PostgreSQL("replica")
        maindb_master - maindb_replica
        grpcsvc >> maindb_master

    maindb_replica >> Airflow("scheduler")

    with Cluster("Sessions HA"):
        session_master = Redis("session")
        session_master - Redis("replica")
        grpcsvc >> session_master

    logaggr = Fluentd("aggregator")
    logaggr >> Kafka("stream") >> Spark("log analytics")
    grpcsvc >> logaggr

    metricq = Kafka("buffer")
    metricq >> Prometheus("metric") >> Grafana("monitoring")

    logaggr >> metricq
    svcmesh >> metricq

    ingress >> svcmesh
```

![on-premise system architecture diagram](/img/on-premise_system_architecture.png)