Aws lambda DynamoDB//Lambda//记录不一致

我们根据事件将数据从应用程序推送到DynamoDB。我们已经编写了一个映射到此DynamoDB表的lambda函数。我们在应用程序中更新的记录已成功发送到DyanamoDB。然而，lambda通常给出较少的记录数

如果在我们的应用程序中更新了3条记录，这三条记录都会被推送到Dynamo，但lambda有时只给出两条或一条记录

我们在lambda函数中构建了一个csv文件，因此csv文件的记录数也更少

我可以分享一些代码片段，但我不知道这是否与Lambda配置或我们用来将数据推送到Dynamo的dynamoapi有关

以下是Lambda代码：

public class ProductLambda implements RequestHandler<DynamodbEvent, String> {
    private static final String M_NUM = "number";
    private static final String FT_TABLE = "table";
    private AmazonS3 s3 = 
    AmazonS3ClientBuilder.standard().withRegion(Regions.US_EAST_1).build();
    private static final String S3_BUCKET = "bucket";
    private static final String S3_FOLDER = "folder";

public ProductLambda() {
}

@Override
public String handleRequest(DynamodbEvent event, Context context) {
    String[] appcol = new String[] {"COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4"};
    String[] fttcol = new String[] {"COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4"};
    
    createFolder(S3_BUCKET, S3_FOLDER, s3);
    List<DynamodbStreamRecord> records = event.getRecords();
    try {
        List<LinkedHashMap<String, AttributeValue>> changedRecords = new ArrayList<LinkedHashMap<String, AttributeValue>>();
        String ddbTable = "";
        for (DynamodbStreamRecord record : records) {
            String modelNumber = "";
            String ddbARN = record.getEventSourceARN();
            if (ddbARN != null) {
                ddbTable = ddbARN.split("/")[1];
            }
            if (record != null) {
                Map<String, AttributeValue> changedRec = record.getDynamodb().getNewImage();
                if (changedRec != null) {
                    if (ddbTable.equalsIgnoreCase("table1")) {
                        LinkedHashMap<String, AttributeValue> staticColumnRecord = new LinkedHashMap<String, AttributeValue>();
                        List<String> list1 = new ArrayList<String>(Arrays.asList(appcol));
                        for (String key : list1) {
                            AttributeValue value = changedRec.get(key);
                            if (value != null) {
                                staticColumnRecord.put(key, value);
                            } else {
                                staticColumnRecord.put(key, new AttributeValue().withS("null"));
                            }
                        }
                        changedRecords.add(staticColumnRecord);
                    }
                    if (ddbTable.equalsIgnoreCase("table2")) {
                        LinkedHashMap<String, AttributeValue> staticColumnRecord = new LinkedHashMap<String, AttributeValue>();
                        List<String> list2 = new ArrayList<String>(Arrays.asList(fttcol));
                        for (String key : list2) {
                            AttributeValue value = changedRec.get(key);
                            if(key.equals("ft_mod")){
                                modelNumber = value.getS();
                            }
                            if (value != null) {
                                staticColumnRecord.put(key, value);
                            } else {
                                staticColumnRecord.put(key, new AttributeValue().withS("null"));
                            }
                        }
                        staticColumnRecord = getModelDetails(staticColumnRecord,modelNumber);
                        changedRecords.add(staticColumnRecord);
                    } 
                }
            }
        }
        context.getLogger().log("[DEBUG] - Total Records Changed: " + changedRecords.size());
        buildAndUploadCSV(changedRecords, context, ddbTable);
    } catch (AmazonServiceException e) {
        context.getLogger().log("[ERROR] - AmazonServiceException " + e);
    } catch (AmazonClientException e) {
        context.getLogger().log("[ERROR] - AmazonClientException " + e);
    } catch (IOException e) {
        context.getLogger().log("[ERROR] - IOException " + e);
    }
    context.getLogger().log("[DEBUG] - Total Records are: " + records.size());
    return "Total records are: " + records.size();
}

/*
 * 
 * @param staticColumnRecord
 * @param modelNumber
 * @param context
 * @return
 */
private LinkedHashMap<String, AttributeValue> getModelDetails(LinkedHashMap<String, AttributeValue> staticColumnRecord,
        String modelNumber) {

    String[] modcol = new String[] { "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4", "COL1", "COL2", "COL3", "COL4" };
    if (!modelNumber.isEmpty()) {
        AmazonDynamoDB dynamoClient = AmazonDynamoDBClientBuilder.standard().build();
        GetItemRequest getItemRequest = new GetItemRequest().withTableName(FT_TABLE)
                .addKeyEntry(M_NUM, new AttributeValue().withS(modelNumber));
        Map<String, AttributeValue> responseItem = dynamoClient.getItem(getItemRequest).getItem();
        List<String> sf_mode_col = new ArrayList<String>(Arrays.asList(modcol));
        if (responseItem != null) {
            for (String key : sf_mode_col) {
                AttributeValue val = responseItem.get(key);
                if (val != null) {
                    staticColumnRecord.put(key, val);
                } else {
                    staticColumnRecord.put(key, new AttributeValue().withS("null"));
                }
            }
        }
    }
    return staticColumnRecord;
}

/*
 * Creates a folder in the S3 bucket.
 */
private static void createFolder(String bucketName, String folderName, AmazonS3 client) {
    ObjectMetadata metadata = new ObjectMetadata();
    metadata.setContentLength(0);
    InputStream emptyContent = new ByteArrayInputStream(new byte[0]);
    PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, folderName, emptyContent, metadata);
    PutObjectResult result = client.putObject(putObjectRequest);
}

/*
 * Build CSV file of changed data and upload to S3 bucket.
 */
private void buildAndUploadCSV(List<LinkedHashMap<String, AttributeValue>> changedRecords, Context context, String tableName)
        throws IOException {
    Calendar calendar = Calendar.getInstance();
    SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
    String outputName = tableName + "_" + formatter.format(calendar.getTime()) + ".csv";
    List<String> headers = changedRecords.stream().flatMap(map -> map.keySet().stream()).distinct()
            .collect(Collectors.toList());
    Path filePath = Paths.get("/tmp", outputName);
    try (OutputStreamWriter bw = new OutputStreamWriter(new FileOutputStream(filePath.toFile()), StandardCharsets.UTF_8)) 
    {
        StringBuffer headerContent = new StringBuffer();
        for (String string : headers) {
            headerContent.append(string);
            headerContent.append(",");
        }
        if (headerContent.length() > 0  && headerContent.charAt(headerContent.length() - 1) == ',')
            headerContent.setLength( headerContent.length() - 1 );

        StringBuffer strBuilder = new StringBuffer();
        for (LinkedHashMap<String, AttributeValue> lmap : changedRecords) {
            StringBuilder stringBuilder = new StringBuilder("");
            String sep = "";
            for (Entry<String, AttributeValue> string2 : lmap.entrySet()) {
                String value = string2.getValue().getS();
                stringBuilder.append(sep).append("\"").append(value).append("\"");
                sep = ",";
            }
            if (!stringBuilder.toString().isEmpty()) {
                strBuilder.append(stringBuilder).append(System.getProperty("line.separator"));
            }
        }
        headerContent.append("\n");
        headerContent.append(strBuilder);
        ByteArrayInputStream contentsAsStream = new ByteArrayInputStream(headerContent.toString().getBytes());
        ObjectMetadata md = new ObjectMetadata();   
        md.setContentLength((long)headerContent.toString().getBytes().length);   
        md.setContentType("text/csv");
        PutObjectRequest request = new PutObjectRequest("bucket", "folder/" + outputName,
                contentsAsStream, md);
        s3.putObject(request);
        bw.flush();
        bw.close();
    } catch (IOException e) {
        context.getLogger().log("[ERROR] - IOException " + e);
    }
}

公共类ProductLambda实现RequestHandler{
私有静态最终字符串M_NUM=“number”；
私有静态最终字符串FT_TABLE=“TABLE”；
私有AmazonS3 s3=
AmazonS3ClientBuilder.standard（）.withRegion（Regions.US_EAST_1.build（）；
私有静态最终字符串S3_BUCKET=“BUCKET”；
私有静态最终字符串S3_FOLDER=“FOLDER”；
公共产品lambda（）{
}
@凌驾
公共字符串handleRequest（DynamodbEvent事件，上下文）{
字符串[]appcol=新字符串[]{“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”}；
字符串[]fttcol=新字符串[]{“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL2”、“COL4”、“COL2”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”}；
createFolder（S3_BUCKET，S3_FOLDER，S3）；
List records=event.getRecords（）；
试一试{
List changedRecords=new ArrayList（）；
字符串ddbTable=“”；
for（DynamodbStreamRecord记录：记录）{
字符串modelNumber=“”；
字符串ddbARN=record.getEventSourceARN（）；
if（ddbARN！=null）{
ddbTable=ddbARN.split（“/”[1]；
}
if（记录！=null）{
Map changedRec=record.getDynamodb（）.getNewImage（）；
if（changedRec！=null）{
if（ddbTable.equalsIgnoreCase（“表1”））{
LinkedHashMap staticColumnRecord=新LinkedHashMap（）；
List list1=新的ArrayList（Arrays.asList（appcol））；
for（字符串键：list1）{
AttributeValue=changedRec.get（键）；
if（值！=null）{
staticColumnRecord.put（键、值）；
}否则{
staticColumnRecord.put（key，new AttributeValue（）.withS（“null”）；
}
}
changedRecords.add（staticColumnRecord）；
}
if（ddbTable.equalsIgnoreCase（“表2”））{
LinkedHashMap staticColumnRecord=新LinkedHashMap（）；
List list2=新的ArrayList（Arrays.asList（fttcol））；
for（字符串键：list2）{
AttributeValue=changedRec.get（键）；
if（键等于（“ft_mod”））{
modelNumber=value.getS（）；
}
if（值！=null）{
staticColumnRecord.put（键、值）；
}否则{
staticColumnRecord.put（key，new AttributeValue（）.withS（“null”）；
}
}
staticColumnRecord=getModelDetails（staticColumnRecord，modelNumber）；
changedRecords.add（staticColumnRecord）；
} 
}
}
}
context.getLogger（）.log（“[DEBUG]-更改的总记录数：”+changedRecords.size（））；
构建并上传CSV（更改记录、上下文、DDB表）；
}捕获（AmazonServiceException e）{
context.getLogger（）.log（“[ERROR]-AmazonServiceException”+e）；
}catch（amazonclientexe）{
context.getLogger（）.log（“[ERROR]-AmazonClientException”+e）；
}捕获（IOE异常）{
context.getLogger（）.log（“[ERROR]-IOException”+e）；
}
context.getLogger（）.log（“[DEBUG]-总记录数为：“+Records.size（））；
return“总记录数为：“+records.size（）”；
}
/*
* 
*@param staticColumnRecord
*@param modelNumber
*@param上下文
*@返回
*/
私有LinkedHashMap getModelDetails（LinkedHashMap staticColumnRecord，
字符串（型号）{
字符串[]modcol=新字符串[]{“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL1”、“COL2”、“COL3”、“COL4”、“COL1”、“COL2”、“COL3”、“COL4”}；
如果（！modelNumber.isEmpty（））{
AmazonDynamoDB dynamoClient=AmazonDynamoDBClientBuilder.standard（）.build（）；
GetItemRequest GetItemRequest=new GetItemRequest（）.withTableName（FT_表）
.addKeyEntry（M_NUM，new AttributeValue（）.with（modelnumer））；
Map responseItem=dynamoClient.getItem（getItemRequest.getItem（）；
List sf_mode_col=newarraylist（Arrays.asList（modcol））；
if（responseItem！=null）{
for（字符串键：sf\U mode\U col）{
AttributeValue val=responseItem.get（键）；
如果（val！=null）{
静态柱状记录