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Timer Trigger¶

This recipe uses Java timer triggers with NCRONTAB schedules, past-due handling, and hosting-plan time-zone behavior.

Architecture¶

flowchart LR
    SCHEDULE[NCRONTAB schedule] --> TIMER[@TimerTrigger]
    TIMER --> WORK[Scheduled work]
    WORK --> LOGS[Execution logs and metrics]

Prerequisites¶

Define a schedule setting:

az functionapp config appsettings set \
  --name $APP_NAME \
  --resource-group $RG \
  --settings "NightlySchedule=0 0 2 * * *"

Time-zone caveat:

WEBSITE_TIME_ZONE is supported on Windows plans and Linux Premium/Dedicated.
WEBSITE_TIME_ZONE is not supported on Linux Consumption or Linux Flex Consumption.

Java implementation¶

package com.contoso.functions;

import com.microsoft.azure.functions.ExecutionContext;
import com.microsoft.azure.functions.TimerInfo;
import com.microsoft.azure.functions.annotation.FunctionName;
import com.microsoft.azure.functions.annotation.TimerTrigger;

public class TimerFunctions {

    @FunctionName("nightlyCleanup")
    public void nightlyCleanup(
        @TimerTrigger(name = "timerInfo", schedule = "%NightlySchedule%") TimerInfo timerInfo,
        final ExecutionContext context
    ) {
        if (timerInfo.isPastDue()) {
            context.getLogger().warning("Timer execution is running past due.");
        }

        context.getLogger().info("Timer fired. Running nightly cleanup job.");
        // Cleanup logic here
    }
}

Implementation notes¶

Use app settings for schedule strings so ops can change cadence without redeploy.
Use isPastDue() to guard expensive work and detect scheduling delays.
Keep timer functions idempotent because missed executions can overlap during recovery.
For business time zones on unsupported Linux plans, convert time in code or use UTC schedules.

See Also¶

Sources¶