Kubernetes Configuration Guide

Specifies the name of the database server.

A Secret is an object that contains a small amount of sensitive data such as a password, a token, or a key and this allows to fetch DB username and password through Kubernetes (k8s) secrets for MySQL DB if db_Enable_Secret is set to Y.

The driver provides Java database connectivity from any Java application, application server, or Java - enabled applet.

MSSQL

SQL Server Driver class includes methods for connecting to a SQL Server database and obtaining information about the JDBC driver.

MYSQL

The MySQL JDBC Driver enables users to connect with live MySQL data, directly from any applications that support JDBC connectivity.

ORACLE

Oracle Driver enables users to dynamically load the driver class file into memory, which automatically registers it.

The general form of the connection URL is as follows:

MSSQL: jdbc:sqlserver://<host_or_ip>:1433;databaseName=<db_name>

MYSQL: jdbc:mysql://<host_or_ip>:3306/<db_name>

Oracle: jdbc:oracle:thin:@<host_or_ip>:1521:<db_name>

host_or_ip: This is the address (optional) of the server to connect to. This can be a DNS or IP address, or it can be localhost or 127.0.0.1 for the local computer. If not specified in the connection URL, the server name must be specified in the properties collection.

port number: This is the port (optional) to connect to serverName. The default is 1433 for mssql , 3306 for mysql, and 1521 for oracle. For the default option, do not specify the port, nor its preceding : in the URL.

db_name: This is the name of the database to be used in sql server.

Indicates the maximum number of connections maintained in the pool.

Indicates the minimum number of connections maintained in the pool.

This contains a list of host or port pairs for establishing the initial connection to the Kafka cluster. A host and port pair uses : as the separator.

• localhost:9092

• localhost:9092,another.host:9092

hostAliases are used to overwrite the resolution of the hostname and IP at the pod level when adding entries to the /etc/hosts file of the pod.

To enable hostAliases, set the below variable to Y.

Docker registry secret contains the Oracle Cloud Infrastructure credentials to use when pulling the image. The user needs to specify the image to pull from Container Registry, including the repository location and the Docker registry secret to use, in the application manifest file.

kubectl create secret docker-registry <secret-name> --docker-server=<region-key>.ocir.io --docker- username='<tenancy-namespace>/<oci-username>' --docker-password='<oci-auth-token>' --docker- email='<email-address>' .

es_Image_Pull_Secret and dbinit_Image_Pull_Secret specifies the <secret-name>, that is used in the manifest file to refer to the already created secret.

The eventstore inbox topic is used to log messages of the events produced.

The eventstore ingester consumer topic is used to log messages of the events that are consumed.

The eventstore ingester error producer logs messages when there is any issue or error when the events are produced.

When creating the POD, one can specify the imagePullPolicyspecification, which guides the Kubelet service on how to pull the specified image during an update.

• If the image pull policy is set to Always, Kubernetes always pulls the image from the Repository.

• With IfNotPresent, Kubernetes only pulls the image when it does not already exist in the node.

• Wth the image pull policy set to Never, Kubernetes never pulls the image.

Docker registry secret contains the Oracle Cloud Infrastructure credentials which the user can use to pull the image. The user needs to specify the image to pull from Container Registry, including the repository location and the docker registry secret to use, in the application manifest file.

kubectl create secret docker-registry <secret-name> --docker-server=<region-key>.o cir.io --docker-username='<tenancy-namespace>/<oci-username>' --docker- password='<oci-auth-token>' --docker-email='<email-address>'.

imagePullSecrets specifies the <secret-name>, that can be used in the manifest file to refer to the already created secret.

Kubernetes deployment informs Kubernetes how to create or modify pod instances that holds a containerized application.

Deployments can scale the number of replica pods, enable the roll out of updated code in a controlled manner, or roll back to an earlier deployment version if necessary.

Specifies the name of the image to be loaded for API, scheduler, ingester, and event delivery during deployment.

This service is responsible for enabling network access to a set of pods.

Specifies the Kubernetes service name for API and ingester.

A Secret is an object that contains a small amount of sensitive data such as a password, a token, or a key which allows to fetch DB username and password through k8s secrets if secret is set to Y.

The driver provides Java database connectivity from any Java application, application server, or Java - enabled applet.

MSSQL

• SQLServerDriver class includes methods for connecting to a SQL Server database and obtaining information about the JDBC driver.

MYSQL

• The MySQL JDBC Driver enables users to connect with live MySQL data, directly from any applications that support JDBC connectivity.

ORACLE

• Oracle Driver enables users to dynamically load the driver class file into memory, which automatically registers it.

The general form of the connection URL is as follows:

MSSQL: jdbc:sqlserver://<host_or_ip>:1433;databaseName=<db_name>

MYSQL: jdbc:mysql://<host_or_ip>:3306/<db_name>

ORACLE: jdbc:oracle:thin:@<host_or_ip>:1521:<db_name>

host_or_ip: This is the address (optional) of the server to connect to. This address can be a DNS or IP address, or it can be localhost or 127.0.0.1 for the local computer. If not specified in the connection URL, the server name must be specified in the properties collection.

port number: This is the port (optional) to connect to on serverName. The default is 1433 for mssql , 3306 for mysql , and 1521 for oracle. If the user is using the default, do not specify the port, nor the preceding : in the URL.

db_name: This is the name of the database to be used in sql server.

Indicates the maximum number of connections maintained in the pool.

Indicates the minimum number of connections maintained in the pool.

Indicates the key or password and algorithm to encrypt the plain text.

These two values are mandatory to encrypt the plain text.

This contains a list of host or port pairs to establish the initial connection of kafka cluster. A host and port pair uses : as the separator.

• localhost:9092

• localhost:9092, another.host:9092.

hostAliases are used to overwrite the resolution of the host name and IP at the pod level when adding entries to the /etc/hosts file.

To enable hostAliases, set the below variables to Y.

This service in Kubernetes is a REST object, similar to a pod. Like all REST objects, the service definition can be posted to the API server to create a new instance.

Specifies the port, type for the eventstore API, and ingester service.

When the Service type is set to load balancer, Kubernetes provides functionality equivalent to type equals ClusterIP to pods within the cluster and extends it by programming the load balancer (external to Kubernetes) with entries for the nodes hosting the relevant Kubernetes pods.

Logging can be collecting, storing, and analyzing distributed logs. Here log stash is used for creating an ingestion pipeline for collecting logs from multiple devices and stored in elastic search for visualizing and analyzing through Grafana.

To enable logging sockethost, SockerPort, and exportType, the protocol should be uncommented, and the required port and host address should be given.

Metrics give us insights into the historical and current state of a system. Data instrumented from microservices are pushed to the PushGateway service. Prometheus collects data from PushGateway at a regular interval. Grafana is used to visualize data in UI.

To enable monitoring in micro services publisherPort, publisherHost can be configured with a push gateway port and host address and metricsDisabled can be changed to false (set to true by default).

Metrics is disabled by default.

Resource management for pods or containers - Kubernetes uses to control resources such as CPU and memory, can declare limits for CPU and for all pod containers.

• cpulimit --The CPU limit defines a hard ceiling on how much CPU time the container can use. It should not be less than 1m (CPU limit can be 1m or 0.001).

• memorylimit – To specify a memory limit for every container in a pod, Kubernetes can infer the pod-level memory limit by adding up the limits for its containers.

• heapLimit

• To change the value of experimental flags, unlock them first. The user can do this by setting -XX:+UnlockExperimentalVMOptions explicitly on the command line before any experimental flags.

• The flag -XX:+UseCGroupMemoryLimitForHeap lets the JVM detect what the max heap size in a container should be.

• MaxRAMPercentage parameter allows setting the maximum heap size for a JVM running with a large amount of memory (greater than 200 MB).