MongoDB TTL索引从不删除记录

Question

我创建了一个索引，如下所示，并为添加到数据库的每条新记录添加了一个 createdAt 字段。记录应该会在 24 小时后自动删除，但是我等了好几天，什么都没有删除。

db_connect.collection("records").createIndex( { "createdAt": 1 }, { expireAfterSeconds: 3600 } )

正在向数据库添加记录

// Add info to db to search
    console.log("Adding info to database..");
    const otherAddress = e.target.address.value;
    const newRecord = {
        holderAddress: this.props.account,
        otherAddress: otherAddress,
        date: new Date(),
        data: encryptedData
    }
    await fetch("http://localhost:420/record/add", {
        method: "POST",
        headers: {
            "Content-Type": "application/json",
        },
        body: JSON.stringify(newRecord),
    }).catch(error => {
        window.alert(error);
    });

它调用的端点：

recordRoutes.route("/record/add").post(function (req, response) {
let db_connect = dbo.getDb();
let myobj = {
    holderAddress: req.body.holderAddress,
    otherAddress: req.body.otherAddress,
    data: req.body.data,
    createdAt: req.body.date
};
db_connect.collection("records").insertOne(myobj, function (err, res) {
    if (err) throw err;
    response.json(res);
});

下面是 MongoDB 网站的截图，确认有一个索引..

输出自：db_connect.collection("records").stats().then(r => { console.log(r)});

 createdAt_1: {
  metadata: [Object],
  creationString: 'access_pattern_hint=none,allocation_size=4KB,app_metadata=(formatVersion=8),assert=(commit_timestamp=none,durable_timestamp=none,read_timestamp=none,write_timestamp=off),block_allocation=best,block_compressor=,cache_resident=false,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=false,extractor=,format=btree,huffman_key=,huffman_value=,ignore_in_memory_cache_size=false,immutable=false,import=(enabled=false,file_metadata=,repair=false),internal_item_max=0,internal_key_max=0,internal_key_truncate=true,internal_page_max=16k,key_format=u,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=16k,leaf_value_max=0,log=(enabled=false),lsm=(auto_throttle=true,bloom=true,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=false,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_custom=(prefix=,start_generation=0,suffix=),merge_max=15,merge_min=0),memory_page_image_max=0,memory_page_max=5MB,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=true,prefix_compression_min=4,readonly=false,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=90,tiered_object=false,tiered_storage=(auth_token=,bucket=,bucket_prefix=,cache_directory=,local_retention=300,name=,object_target_size=10M),type=file,value_format=u,verbose=[],write_timestamp_usage=none',
  type: 'file',
  uri: 'statistics:table:index-3854-9052224765860348301',
  LSM: [Object],
  'block-manager': [Object],
  btree: [Object],
  cache: [Object],
  cache_walk: [Object],
  'checkpoint-cleanup': [Object],
  compression: [Object],
  cursor: [Object],
  reconciliation: [Object],
  session: [Object],
  transaction: [Object]
}

非常感谢任何帮助！

Answer 1

数据过期要求索引字段值是一个 BSON 日期，或一个 BSON 日期数组。

MongoDB Reference Manual

Expiration of Data
TTL indexes expire documents after the specified number of seconds
has passed since the indexed field value; i.e. the expiration threshold
is the indexed field value plus the specified number of seconds.

If the field is an array, and there are multiple date values in the index,
MongoDB uses lowest (i.e. earliest) date value in the array to calculate
the expiration threshold.

If the indexed field in a document is not a date or an array that holds
one or more date values, the document will not expire.

If a document does not contain the indexed field, the document will not
expire.

MongoDB TTL索引从不删除记录

MongoDB TTL index never deletes records

javascript

ttl

mongodb

database-indexes

mongodb-indexes