Question

我们有一个Web服务feed，每天运行，并将所有文档保存到CosmosDB集合中，因为随着新feed的出现，我不需要保留旧文档，所以我每天要删除并重新创建集合好，这有一些缺点

重置了集合的统计信息，因此对应用的见解和日志记录变得无用
几乎所有日志等也都将重置，因此几乎不可能排除故障

如何在添加新文档之前清空CosmosDB集合，以便保留所有指标等？

这是我目前正在做的

log.LogInformation("XXX--> Deleting Collection");
await docClient.DeleteDocumentCollectionAsync(collectionLink);

log.LogInformation("XXX--> Creating Collection");
defaultCollection = await docClient.CreateDocumentCollectionIfNotExistsAsync(databaseLink, defaultCollection, new RequestOptions { OfferThroughput = 1000 });

我想要相同的结果，但保留所有统计信息等。

Answer 1

您可以创建一个批量删除存储过程，以从集合中删除所有文档，而不是删除集合。

可以在以下位置找到这种存储过程的有效实现：https://github.com/CosmosDB/labs/blob/3f49d8af44468ff7640cd3e382d13ba4c0299249/solutions/05-authoring_stored_procedures/bulk_delete.js

/**
 * A DocumentDB stored procedure that bulk deletes documents for a given query.<br/>
 * Note: You may need to execute this stored procedure multiple times (depending whether the stored procedure is able to delete every document within the execution timeout limit).
 *
 * @function
 * @param {string} query - A query that provides the documents to be deleted (e.g. "SELECT c._self FROM c WHERE c.founded_year = 2008"). Note: For best performance, reduce the # of properties returned per document in the query to only what's required (e.g. prefer SELECT c._self over SELECT * )
 * @returns {Object.<number, boolean>} Returns an object with the two properties:<br/>
 *   deleted - contains a count of documents deleted<br/>
 *   continuation - a boolean whether you should execute the stored procedure again (true if there are more documents to delete; false otherwise).
 */
function bulkDeleteProcedure(query) {
    var collection = getContext().getCollection();
    var collectionLink = collection.getSelfLink();
    var response = getContext().getResponse();
    var responseBody = {
        deleted: 0,
        continuation: true
    };

    // Validate input.
    if (!query) throw new Error("The query is undefined or null.");

    tryQueryAndDelete();

    // Recursively runs the query w/ support for continuation tokens.
    // Calls tryDelete(documents) as soon as the query returns documents.
    function tryQueryAndDelete(continuation) {
        var requestOptions = {continuation: continuation};

        var isAccepted = collection.queryDocuments(collectionLink, query, requestOptions, function (err, retrievedDocs, responseOptions) {
            if (err) throw err;

            if (retrievedDocs.length > 0) {
                // Begin deleting documents as soon as documents are returned form the query results.
                // tryDelete() resumes querying after deleting; no need to page through continuation tokens.
                //  - this is to prioritize writes over reads given timeout constraints.
                tryDelete(retrievedDocs);
            } else if (responseOptions.continuation) {
                // Else if the query came back empty, but with a continuation token; repeat the query w/ the token.
                tryQueryAndDelete(responseOptions.continuation);
            } else {
                // Else if there are no more documents and no continuation token - we are finished deleting documents.
                responseBody.continuation = false;
                response.setBody(responseBody);
            }
        });

        // If we hit execution bounds - return continuation: true.
        if (!isAccepted) {
            response.setBody(responseBody);
        }
    }

    // Recursively deletes documents passed in as an array argument.
    // Attempts to query for more on empty array.
    function tryDelete(documents) {
        if (documents.length > 0) {
            // Delete the first document in the array.
            var isAccepted = collection.deleteDocument(documents[0]._self, {}, function (err, responseOptions) {
                if (err) throw err;

                responseBody.deleted++;
                documents.shift();
                // Delete the next document in the array.
                tryDelete(documents);
            });

            // If we hit execution bounds - return continuation: true.
            if (!isAccepted) {
                response.setBody(responseBody);
            }
        } else {
            // If the document array is empty, query for more documents.
            tryQueryAndDelete();
        }
    }
}

如何清空CosmosDB集合并再次填充它并保留其度量标准/日志

1 个答案: