This chapter discusses the process for deploying active standby pairs of TimesTen databases. It describes the process for creating TimesTenClassic objects in your environment. It also provides examples that demonstrate how to monitor the provisioning of the active standby pair of TimesTen databases. The chapter concludes with examples that show you how to connect to the database and run operations in it.
Topics:
The TimesTen Operator extends the Kubernetes API to provide the TimesTenClassic object type. This type provides the definitions you need to successfully deploy your TimesTen databases to the Kubernetes cluster. You customize these definitions for your particular environment. Specifically, you create a YAML file and, in it, you specify the required TimesTenClassic definitions for the TimesTenClassic object. By assigning values to the fields of these definitions, you customize and define your deployment environment. For example, when you supply the oci value for the storageClassName field, you are telling the Operator the name of the storage class you want to use. See Chapter 11, "The TimesTenClassic Object Type" for the object definitions, and the fields that you define in your YAML file.
Examples of the YAML file were introduced previously when discussing ConfigMaps and Secrets, an init container, and other configuration options. (See "Using ConfigMaps and Secrets" for information on ConfigMaps and Secrets. Also see "Using an init container" and "Additional configuration options" for other configuration options.) However, "Defining and creating the TimesTenClassic object" shows you how to define the TimesTenClassic object in detail.
After specifying your configuration in the YAML file, you use the kubectl create command from your Linux development host to create the corresponding TimesTenClassic object in your cluster. After you issue this command, the process for deploying your active standby pair of TimesTen databases begins. You can view this process by issuing kubectl get and kubectl describe commands, such as, kubectl get pods and kubectl describe timestenclassic. Once your databases are deployed, you can then connect to your active database, issue queries, and perform other operations to verify your database is working as it should.
Defining your environment involves creating TimesTenClassic objects with attributes customized for your environment. The fields include the name of the image pull secret, the name of your TimesTen image, and the other definitions required to successfully deploy your TimesTen databases. See "The TimesTenClassic object type" for information on defining objects of type TimesTenClassic.
Perform these steps to define and create the TimesTenClassic object:
Create an empty YAML file. You can choose any name, but you may want to use the same name you used for the name of the TimesTenClassic object. (In this example, sample.) The YAML file contains the definitions for the TimesTenClassic object. See "TimesTenClassicSpecSpec" for information on the fields that you must specify in this YAML file as well as the fields that are optional.
In this example, replace the following. (The values you can replace are represented in bold.)
name: Replace sample with the name of your TimesTenClassic object.
storageClassName: Replace oci with the name of the storage class used to allocate PersistentVolumes to hold TimesTen.
storageSize: Replace 250G with the amount of storage that should be requested for each Pod to hold TimesTen. (This example assumes a production environment and uses 250G for storage. For demonstration purposes, you can use 50G of storage. See the storageSize and the logStorageSize entries in the Table 11-3, "TimesTenClassicSpecSpec" for information.)
image: Replace phx.ocir.io/youraccount/tt1814110:3 with the location of the image registry (phx.ocir.io/youraccount) and the image containing TimesTen (tt1814110:3).
imagePullSecret: Replace sekret with the image pull secret that Kubernetes should use to fetch the TimesTen image.
dbConfigMap: This example uses one ConfigMap (called sample) for the db.ini, the adminUser, and the schema.sql metadata files. This ConfigMap will be included in the ProjectedVolume. This volume is mounted as /ttconfig in the TimesTen containers. See "Using ConfigMaps and Secrets" and "Example using one ConfigMap" for information on ConfigMaps.
% vi sample.yaml apiVersion: timesten.oracle.com/v1 kind: TimesTenClassic metadata: name: sample spec: ttspec: storageClassName: oci storageSize: 250G image: phx.ocir.io/youraccount/tt1814110:3 imagePullSecret: sekret dbConfigMap: - sample
Use the kubectl create command to create the TimesTenClassic object from the contents of the YAML file (in this example, sample.yaml). Doing so begins the process of deploying your active standby pair of TimesTen databases in the Kubernetes cluster.
% kubectl create -f sample.yaml timestenclassic.timesten.oracle.com/sample created
You successfully created the TimesTenClassic object in the Kubernetes cluster. The process of deploying your TimesTen databases begins, but is not yet complete.
You can use various kubectl commands to monitor the progress of the active standby pair deployment. After the deployment is complete and successful, you can connect to the database and run operations in it to verify it is working as it should.
Use the kubectl get and the kubectl describe commands to monitor the progress of the active standby pair as it is provisioned.
Note:
For thekubectl get timestenclassic and kubectl describe timestenclassic commands, you can alternatively specify kubectl get ttc and kubectl describe ttc respectively. timestenclassic and ttc are synonymous when used in these commands, and return the same results. The first kubectl get and the first kubectl describe examples in this chapter use timestenclassic. The remaining examples in this book use ttc for simplicity.Use the kubectl get command and review the STATE field. Observe the value is Initializing. The active standby pair provisioning has begun, but is not yet complete.
% kubectl get timestenclassic sample NAME STATE ACTIVE AGE sample Initializing None 11s
Use the kubectl describe command to view the initial provisioning in detail.
% kubectl describe timestenclassic sample
Name: sample
Namespace: mynamespace
Labels: <none>
Annotations: <none>
API Version: timesten.oracle.com/v1
Kind: TimesTenClassic
Metadata:
Creation Timestamp: 2020-05-31T15:35:12Z
Generation: 1
Resource Version: 20231755
Self Link:
/apis/timesten.oracle.com/v1/namespaces/mynamespace/timestenclassics/sample
UID: 517a8646-a354-11ea-a9fb-0a580aed5e4a
Spec:
Ttspec:
Db Config Map:
sample
Image: phx.ocir.io/youraccount/tt1814110:3
Image Pull Policy: Always
Image Pull Secret: sekret
Storage Class Name: oci
Storage Size: 250G
Status:
Active Pods: None
High Level State: Initializing
Last Event: 3
Pod Status:
Cache Status:
Cache Agent: Down
Cache UID Pwd Set: false
N Cache Groups: 0
Db Status:
Db: Unknown
Db Id: 0
Db Updatable: Unknown
Initialized: true
Pod Status:
Agent: Down
Last Time Reachable: 0
Pod IP:
Pod Phase: Pending
Replication Status:
Last Time Rep State Changed: 0
Rep Agent: Down
Rep Peer P State: Unknown
Rep Scheme: Unknown
Rep State: Unknown
Times Ten Status:
Daemon: Down
Instance: Unknown
Release: Unknown
Admin User File: false
Cache User File: false
Cg File: false
High Level State: Down
Intended State: Active
Name: sample-0
Schema File: false
Cache Status:
Cache Agent: Down
Cache UID Pwd Set: false
N Cache Groups: 0
Db Status:
Db: Unknown
Db Id: 0
Db Updatable: Unknown
Initialized: true
Pod Status:
Agent: Down
Last Time Reachable: 0
Pod IP:
Pod Phase: Pending
Replication Status:
Last Time Rep State Changed: 0
Rep Agent: Down
Rep Peer P State: Unknown
Rep Scheme: Unknown
Rep State: Unknown
Times Ten Status:
Daemon: Down
Instance: Unknown
Release: Unknown
Admin User File: false
Cache User File: false
Cg File: false
High Level State: Unknown
Intended State: Standby
Name: sample-1
Schema File: false
Rep Create Statement: create active standby pair "sample" on
"sample-0.sample.mynamespace.svc.cluster.local", "sample" on
"sample-1.sample.mynamespace.svc.cluster.local" NO RETURN store "sample" on
"sample-0.sample.mynamespace.svc.cluster.local" PORT 4444 FAILTHRESHOLD 0
store "sample" on "sample-1.sample.mynamespace.svc.cluster.local" PORT 4444
FAILTHRESHOLD 0
Rep Port: 4444
Status Version: 1.0
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
- Create 50s ttclassic Secret tt517a8646-a354-11ea-a9fb-0a580aed5e4a
created
- Create 50s ttclassic Service sample created
- Create 50s ttclassic StatefulSet sample created
Use the kubectl get command again to see if value of the STATE field has changed. In this example, the value is Normal, indicating the active standby pair of databases are now provisioned and the process is complete.
% kubectl get ttc sample NAME STATE ACTIVE AGE sample Normal sample-0 3m5s
Use the kubectl describe command again to view the active standby pair provisioning in detail.
Note: In this example, the now Normal line displays on its own line. In the actual output, this line does not display as its own line, but at the end of the StateChange previous line.
% kubectl describe ttc sample
Name: sample
Namespace: mynamespace
Labels: <none>
Annotations: <none>
API Version: timesten.oracle.com/v1
Kind: TimesTenClassic
Metadata:
Creation Timestamp: 2020-05-31T15:35:12Z
Generation: 1
Resource Version: 20232668
Self Link:
/apis/timesten.oracle.com/v1/namespaces/mynamespace/timestenclassics/sample
UID: 517a8646-a354-11ea-a9fb-0a580aed5e4a
Spec:
Ttspec:
Db Config Map:
sample
Image: phx.ocir.io/youraccount/tt1814110:3
Image Pull Policy: Always
Image Pull Secret: sekret
Storage Class Name: oci
Storage Size: 250G
Status:
Active Pods: sample-0
High Level State: Normal
Last Event: 35
Pod Status:
Cache Status:
Cache Agent: Not Running
Cache UID Pwd Set: true
N Cache Groups: 0
Db Status:
Db: Loaded
Db Id: 26
Db Updatable: Yes
Initialized: true
Pod Status:
Agent: Up
Last Time Reachable: 1590939597
Pod IP: 192.0.2.1
Pod Phase: Running
Replication Status:
Last Time Rep State Changed: 0
Rep Agent: Running
Rep Peer P State: start
Rep Scheme: Exists
Rep State: ACTIVE
Times Ten Status:
Daemon: Up
Instance: Exists
Release: 18.1.4.11.0
Admin User File: true
Cache User File: false
Cg File: false
High Level State: Healthy
Intended State: Active
Name: sample-0
Schema File: true
Cache Status:
Cache Agent: Not Running
Cache UID Pwd Set: true
N Cache Groups: 0
Db Status:
Db: Loaded
Db Id: 26
Db Updatable: No
Initialized: true
Pod Status:
Agent: Up
Last Time Reachable: 1590939597
Pod IP: 192.0.2.2
Pod Phase: Running
Replication Status:
Last Time Rep State Changed: 1590939496
Rep Agent: Running
Rep Peer P State: start
Rep Scheme: Exists
Rep State: STANDBY
Times Ten Status:
Daemon: Up
Instance: Exists
Release: 18.1.4.11.0
Admin User File: true
Cache User File: false
Cg File: false
High Level State: Healthy
Intended State: Standby
Name: sample-1
Schema File: true
Rep Create Statement: create active standby pair "sample" on
"sample-0.sample.mynamespace.svc.cluster.local", "sample" on
"sample-1.sample.mynamespace.svc.cluster.local" NO RETURN store "sample" on
"sample-0.sample.mynamespace.svc.cluster.local" PORT 4444 FAILTHRESHOLD 0
store "sample" on "sample-1.sample.mynamespace.svc.cluster.local" PORT 4444
FAILTHRESHOLD 0
Rep Port: 4444
Status Version: 1.0
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
- Create 4m43s ttclassic Secret
tt517a8646-a354-11ea-a9fb-0a580aed5e4a created
- Create 4m43s ttclassic Service sample created
- Create 4m43s ttclassic StatefulSet sample created
- StateChange 3m47s ttclassic Pod sample-0 Daemon Unknown
- StateChange 3m47s ttclassic Pod sample-0 CacheAgent Unknown
- StateChange 3m47s ttclassic Pod sample-0 RepAgent Unknown
- StateChange 3m47s ttclassic Pod sample-1 Daemon Unknown
- StateChange 3m47s ttclassic Pod sample-1 CacheAgent Unknown
- StateChange 3m47s ttclassic Pod sample-1 RepAgent Unknown
- StateChange 3m26s ttclassic Pod sample-0 Agent Up
- StateChange 3m26s ttclassic Pod sample-0 Release 18.1.4.11.0
- StateChange 3m26s ttclassic Pod sample-0 Daemon Down
- StateChange 3m26s ttclassic Pod sample-1 Agent Up
- StateChange 3m26s ttclassic Pod sample-1 Release 18.1.4.11.0
- StateChange 3m26s ttclassic Pod sample-1 Daemon Down
- StateChange 3m26s ttclassic Pod sample-0 Daemon Up
- StateChange 3m25s ttclassic Pod sample-1 Daemon Up
- StateChange 2m13s ttclassic Pod sample-0 RepState IDLE
- StateChange 2m13s ttclassic Pod sample-0 Database Updatable
- StateChange 2m13s ttclassic Pod sample-0 CacheAgent Not Running
- StateChange 2m13s ttclassic Pod sample-0 RepAgent Not Running
- StateChange 2m13s ttclassic Pod sample-0 RepScheme None
- StateChange 2m13s ttclassic Pod sample-0 Database Loaded
- StateChange 2m11s ttclassic Pod sample-0 RepAgent Running
- StateChange 2m10s ttclassic Pod sample-0 RepScheme Exists
- StateChange 2m10s ttclassic Pod sample-0 RepState ACTIVE
- StateChange 113s ttclassic Pod sample-1 Database Loaded
- StateChange 113s ttclassic Pod sample-1 Database Not Updatable
- StateChange 113s ttclassic Pod sample-1 CacheAgent Not Running
- StateChange 113s ttclassic Pod sample-1 RepAgent Not Running
- StateChange 113s ttclassic Pod sample-1 RepScheme Exists
- StateChange 113s ttclassic Pod sample-1 RepState IDLE
- StateChange 106s ttclassic Pod sample-1 RepAgent Running
- StateChange 101s ttclassic Pod sample-1 RepState STANDBY
- StateChange 101s ttclassic TimesTenClassic was Initializing,
now Normal
Your active standby pair of TimesTen databases are successfully deployed (as indicated by Normal.) There are two TimesTen databases, configured as an active standby pair. One database is active. (In this example, sample-0 is the active database, as indicated by Rep State ACTIVE). The other database is standby. (In this example, sample-1 is the standby database as indicated by Rep State STANDBY). The active database can be modified and queried. Changes made on the active database are replicated to the standby database. If the active database fails, the Operator automatically promotes the standby database to be the active. The formerly active database will be repaired or replaced, and will then become the standby.
The Operator creates other underlying objects automatically. Verify that these objects are created.
StatefulSet:
% kubectl get statefulset sample NAME READY AGE sample 2/2 8m21s
Service:
% kubectl get service sample NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE sample ClusterIP None <none> 6625/TCP 9m28s
Pods:
% kubectl get pods NAME READY STATUS RESTARTS AGE sample-0 2/2 Running 0 10m sample-1 2/2 Running 0 10m timestenclassic-operator-5d7dcc7948-8mnz4 1/1 Running 0 11h
PersistentVolumeClaims (PVCs):
% kubectl get pvc NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE tt-persistent-sample-0 Bound ocid1.volume.oc1.phx.abyhqljrbxcgzyixa4pmmcwiqxgqclc7gxvdnoty367w2qn26tij6kfpx 6qq 250Gi RWO oci 10m tt-persistent-sample-1 Bound ocid1.volume.oc1.phx.abyhqljtt4qxxoj5jqiskriskh66hakaw326rbza4uigmuaezdnu53qhh oaa 250Gi RWO oci 10m
You can run the kubectl exec command to invoke shells in your Pods and control TimesTen, which is running in those Pods. TimesTen runs in the Pods as the oracle user. Once you have established a shell in the Pod, use the su - oracle command to switch to the oracle user. After you switch to the oracle user, verify you can connect to the sample database, and that the information from the metadata files is correct. You can optionally run queries against the database or any other operations.
Establish a shell in the Pod and switch to the oracle user.
% kubectl exec -it sample-0 -c tt -- /usr/bin/su - oracle
Connect to the sample database. Verify the information in the metadata files is in the database correctly. For example, attempt to connect to the database as the scott user. Check that the PermSize value of 200 is correct. Check that the scott.emp table exists.
% ttIsql sample Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved. Type ? or "help" for help, type "exit" to quit ttIsql. connect "DSN=sample"; Connection successful: DSN=sample;UID=oracle;DataStore=/tt/home/oracle/datastore/sample; DatabaseCharacterSet=AL32UTF8;ConnectionCharacterSet=US7ASCII;PermSize=200; DDLReplicationLevel=3; (Default setting AutoCommit=1) Command> connect adding "uid=scott;pwd=tiger" as scott; Connection successful: DSN=sample;UID=scott;DataStore=/tt/home/oracle/datastore/sample; DatabaseCharacterSet=AL32UTF8;ConnectionCharacterSet=US7ASCII;PermSize=200; DDLReplicationLevel=3; (Default setting AutoCommit=1) scott: Command> tables; SCOTT.EMP 1 table found.