使用 Pentaho Kettle，如何自動重試由於連接問題而失敗的休息請求？

Question

我們如何讓 Pentaho 在連接錯誤時重試 rest 請求？

我們有一個 Pentaho BI 系統，它在眾多數據源中查詢特定 REST api，每次運行超過 20k 查詢變體。

可以預見，在大多數運行中，這些請求中的一些會由於連接問題而失敗。 這些通常在 Pentaho 日志中表現為org.pentaho.di.core.exception.KettleException由於javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake ，最終由java.io.EOFException: SSL peer shut down incorrectly引起java.io.EOFException: SSL peer shut down incorrectly 。

在搜索互聯網和 Pentaho 論壇后，我們找不到任何關於在這種情況下添加簡單重試方法的說明。 頭發正在被扯掉。

更新 1：堆棧跟蹤：

ERROR 29-11 11:02:17,659 - B - org.pentaho.di.core.exception.KettleException:
Can not result from [https://<DOMAIN>/<PATH>?<PARAMS>]
javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake    
    at org.pentaho.di.trans.steps.rest.Rest.callRest(Rest.java:190)
    at org.pentaho.di.trans.steps.rest.Rest.processRow(Rest.java:385)
    at org.pentaho.di.trans.step.RunThread.run(RunThread.java:40)
    at java.lang.Thread.run(Thread.java:662)
Caused by: com.sun.jersey.api.client.ClientHandlerException: javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake
    at com.sun.jersey.client.apache.DefaultApacheHttpMethodExecutor.executeMethod(DefaultApacheHttpMethodExecutor.java:213)
    at com.sun.jersey.client.apache.ApacheHttpClientHandler.handle(ApacheHttpClientHandler.java:175)
    at com.sun.jersey.api.client.filter.HTTPBasicAuthFilter.handle(HTTPBasicAuthFilter.java:81)
    at com.sun.jersey.api.client.Client.handle(Client.java:648)
    at com.sun.jersey.api.client.WebResource.handle(WebResource.java:670)
    at com.sun.jersey.api.client.WebResource.get(WebResource.java:191)
    at org.pentaho.di.trans.steps.rest.Rest.callRest(Rest.java:141)
    ... 3 more
Caused by: javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:817)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1138)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:632)
    at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:59)
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
    at org.apache.commons.httpclient.HttpConnection.flushRequestOutputStream(HttpConnection.java:827)
    at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.flushRequestOutputStream(MultiThreadedHttpConnectionManager.java:1525)
    at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:1975)
    at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:993)
    at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:397)
    at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:170)
    at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:396)
    at com.sun.jersey.client.apache.DefaultApacheHttpMethodExecutor.executeMethod(DefaultApacheHttpMethodExecutor.java:210)
    ... 9 more
Caused by: java.io.EOFException: SSL peer shut down incorrectly
    at com.sun.net.ssl.internal.ssl.InputRecord.read(InputRecord.java:333)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:798)
    ... 22 more

Answer 1

或者在其余客戶端步驟上使用步驟錯誤處理，並將錯誤字段定向到另一個其余客戶端步驟。

顯然，這只能讓您根據步驟重試多少次，但無論如何重試一次都沒有意義。

Answer 2

使用來源，盧克。

在 org.pentaho.di.trans.steps.rest.Rest.processRow(Rest.java:385) 你會發現

    } catch(KettleException e) {
         boolean sendToErrorRow=false;
         String errorMessage = null;

        if (getStepMeta().isDoingErrorHandling()){
             sendToErrorRow = true;
             errorMessage = e.toString();
        } else {
            logError(BaseMessages.getString(PKG, "Rest.ErrorInStepRunning")+e.getMessage()); //$NON-NLS-1$
            setErrors(1);
            logError(Const.getStackTracker(e));
            stopAll();
            setOutputDone();  // signal end to receiver(s)
            return false;
        }

        if (sendToErrorRow) {
           // Simply add this row to the error row
           putError(getInputRowMeta(), r, 1, errorMessage, null, "Rest001");
        }

    }

看來您可以按行配置錯誤處理。 這似乎就是你所追求的。