MongoDB Timeseries unusably slow queries after deleting and re-creating timeseries with auto-deletion - mongodb

Question

My measurements:
I have 3 measurement types, a lot of assets, and data with timestamps. The size of the timeseries grows by ~5GB / month after compression.
My timeseries collections:
I had a blank timeseries DB initially. It was slow so I indexed it, it became actually extremely fast and handy to use. After a few months, it became too large. I couldn't delete old entries in time, so I had to drop it. It became unusable.
I have created a new one, with automatic deletion. I indexed it in 2 ways.
.createIndex({measurement:1, asset:1, timestamp:1})
.createIndex({asset:1, measurement:1, timestamp:1})
Each and every query for a single asset's measurement type, limited to 1000 takes upwards of 2 minutes, if it ever returns at all.
Example:
{asset:"my_asset", measurement:"price"}
{measurement:"price", asset:"my_asset"}
The database is unusable on arrival. It was never functional, from the very start, with or without indexing the queries were unbearably slow.
The fastest query, which sometimes returns something, I found in MongoDB Compass. Using the indexes, just querying {asset:"my_asset"} with all the types and without limits, seems to be faster than querying into literally the easiest index to navigate, I don't know how on earth there could be a better index and how any query can take longer than a second. Literally, having it indexed by measurement type cuts off 66% of bilions of other entries initially, then asset: narrows down the asset and how can this take longer than a second?
This is the server's snippet code that makes the call.
let doc = doc!{
"measurement":measurement, //reverse order due to index measure//timest.
"asset":asset
};
let find_options = FindOptions::builder()
.projection(doc! {
"timestamp": 1,
"data": 1,
})
.limit(1000)
.build();
let res = coll.find(doc, find_options).await.unwrap();
Example of an op
{
"type": "op",
"host": "---",
"desc": "---",
"connectionId": 80806,
"client": "---",
"clientMetadata": {
"driver": {
"name": "mongo-rust-driver",
"version": "2.3.1"
},
"os": {
"type": "linux",
"architecture": "x86_64",
"version": "18.04"
},
"platform": "rustc 1.67.0-nightly (1eb62b123 2022-11-27) with tokio"
},
"active": "true",
"currentOpTime": "2023-02-18T16:09:00.569+00:00",
"effectiveUsers": [
{
"user": "---",
"db": "---"
}
],
"threaded": true,
"opid": 4359443,
"lsid": {
"id": "---",
"uid": "---"
},
"secs_running": 1255,
"microsecs_running": 1255159150,
"op": "getmore",
"ns": "MyDB.MyTS",
"command": {
"getMore": {
"low": 1168443057,
"high": 1271883998,
"unsigned": false
},
"collection": "MyTS",
"$db": "MyDB",
"lsid": {
"id": "---"
},
"$clusterTime": {
"clusterTime": {
"$timestamp": "7201527765789573142"
},
"signature": {
"hash": "---",
"keyId": {
"low": 6,
"high": 1669480924,
"unsigned": false
}
}
},
"$readPreference": {
"mode": "primaryPreferred"
}
},
"planSummary": "IXSCAN { control.min.measurement: 1, control.max.measurement: 1, control.min.asset: 1, control.max.asset: 1, control.min.timestamp: 1, control.max.timestamp: 1 }",
"cursor": {
"cursorId": {
"low": 1168443057,
"high": 1271883998,
"unsigned": false
},
"createdDate": "2023-02-18T16:04:56.238Z",
"lastAccessDate": "2023-02-18T16:05:47.456Z",
"nDocsReturned": 0,
"nBatchesReturned": 1,
"noCursorTimeout": false,
"tailable": false,
"awaitData": false,
"originatingCommand": {
"aggregate": "system.buckets.MyTS",
"pipeline": [
{
"$_internalUnpackBucket": {
"timeField": "timestamp",
"bucketMaxSpanSeconds": 86400,
"exclude": [],
"assumeNoMixedSchemaData": true
}
},
{
"$match": {
"measurement": "price",
"asset": "myAsset"
}
},
{
"$limit": 1000
},
{
"$project": {
"timestamp": 1,
"data": 1
}
}
],
"cursor": {
"batchSize": 101
},
"collation": {}
},
"operationUsingCursorId": 4359443
},
"numYields": 4224,
"locks": {},
"waitingForLock": "false",
"lockStats": {
"FeatureCompatibilityVersion": {
"acquireCount": {
"r": 4480
}
},
"Global": {
"acquireCount": {
"r": 4480
}
},
"Mutex": {
"acquireCount": {
"r": 256
}
}
},
"waitingForFlowControl": false,
"flowControlStats": {}
}
It returned after 32 minutes. It used to take 3 seconds, maximum.