Wait for AWS Athena query execution in Go SDK-CodePudding

I have a working code that runs an Athena Query and waits for the query to finish by polling the error return from GetQueryResults using the following code:

func GetQueryResults(client *athena.Client, QueryID *string) []types.Row {

    params := &athena.GetQueryResultsInput{
        QueryExecutionId: QueryID,
    }

    data, err := client.GetQueryResults(context.TODO(), params)

    for err != nil {
        println(err.Error())
        time.Sleep(time.Second)
        data, err = client.GetQueryResults(context.TODO(), params)
    }

    return data.ResultSet.Rows
}

The problem is that in case the query fails, I have absolutely no way to break the loop.

For example, in Python I can do something like:

    while athena.get_query_execution(QueryExecutionId=execution_id)["QueryExecution"][
        "Status"
    ]["State"] in ["RUNNING", "QUEUED"]:
        sleep(2)

I can do a check like strings.Contains(err.Error(),"FAILED") inside the for loop, but I am looking for a cleaner way.

I tried looking for an equivalent for Go, but I wasn't successful. Is there a function for Go SDK that can return the execution status? Is there a better way to further examine an error in Go instead of err != nil?

CodePudding user response：

The SDK has already provided retries.

Here is an example for you, using aws-sdk-go-v2.

package main

import (
    "context"
    "fmt"
    "time"

    "github.com/aws/aws-sdk-go-v2/aws"
    "github.com/aws/aws-sdk-go-v2/service/athena"
    "github.com/aws/aws-sdk-go-v2/service/athena/types"
)

func main() {
    cfg := aws.NewConfig()
    ath := athena.NewFromConfig(*cfg)

    ctx, cancelFunc := context.WithTimeout(context.Background(), time.Minute*5)
    defer cancelFunc()

    rows, err := GetQueryResults(ctx, ath, aws.String("query-id"), 10)
    if err != nil {
        panic(err) // TODO: handle error
    }

    fmt.Println(rows)
}

func GetQueryResults(ctx context.Context, client *athena.Client, QueryID *string, attempts int) ([]types.Row, error) {
    t := time.NewTicker(time.Second * 5)
    defer t.Stop()

    attemptsFunc := func(o *athena.Options) { o.RetryMaxAttempts = attempts }

WAIT:
    for {
        select {
        case <-t.C:
            out, err := client.GetQueryExecution(ctx, &athena.GetQueryExecutionInput{
                QueryExecutionId: QueryID,
            }, attemptsFunc)
            if err != nil {
                return nil, err
            }

            switch out.QueryExecution.Status.State {
            case types.QueryExecutionStateCancelled,
                types.QueryExecutionStateFailed,
                types.QueryExecutionStateSucceeded:
                break WAIT
            }

        case <-ctx.Done():
            break WAIT
        }
    }

    data, err := client.GetQueryResults(ctx, &athena.GetQueryResultsInput{
        QueryExecutionId: QueryID,
    })
    if err != nil {
        return nil, err
    }

    return data.ResultSet.Rows, nil
}