Oof, that 90-second cliff is brutal, but I'm not surprised. Their official ingestion pipeline is tuned for generalized enterprise telemetry, not high-frequency security agent logs. The 500s mixed with the 429s tell me their autoscaling is struggling with your burst pattern.
I saw similar spikes when I was pushing AutoGPT audit logs through their V2 endpoint last year. The trick was to stop treating it like a firehose and start using the metadata fields for load shedding. Can you tag your events with a `metadata.severity` or `metadata.event_type` priority? We started dropping `INFO` level seccomp audits (like benign policy checks) during congestion spikes, preserving only the `ALERT` and `WARNING` events for causality. It's not perfect, but it kept the detection-critical stuff in order.
Also, double-check your `principal.hostname` field length. I got burned by them truncating anything over 253 chars silently, which caused batch rejections later. That might be adding to your error load.
2.5k/sec per host and you're batching straight to JSON UDM? That's your first problem. The overhead's killing you before it even leaves the machine.
You need a local buffer that's not in memory. `bbolt` or `sqlite` with a staged table, keyed by the original agent timestamp. Dequeue in chronological order, but batch by *forwarder receipt time* windows to avoid the timeline scramble on retries. It's not perfect causality but it's stable.
Also, ditch the official Go SDK for raw HTTP with a tuned transport. The SDK's retry logic is trash for this volume.
Patch early, patch often.
Wow, 2,5k events per second is nuts. I just started reading about this stuff. So if you lose the timeline order on retries, does that mean your security alerts could be out of sequence? Like, seeing a file access before you see the process that opened it?
Also, are the 500s you're getting actual internal server errors, or could they be a weird side effect of the batching? I've seen APIs get confused with big JSON payloads.
Yeah, the causality problem you're describing is exactly right. Seeing a file access logged before the process launch that caused it can completely break your detection rules.
The 500s are probably real service hiccups under load, but you're also onto something about batching side effects. If a batch partially fails or a nested JSON structure is malformed due to a bug in your aggregation, the whole payload can get rejected with a generic 5xx error. I've seen it happen when a single event in a 10k batch has an integer overflow.
Best fix for the timeline scramble is to include a sequence ID from the agent *and* a forwarder ingestion timestamp. You can reconstruct order on the backend if you have both.
--Al
You've hit on the core issue: "paying them to store logs you just admitted are too slow for detection." This assumes the primary value of a SIEM is real-time detection. For many models of investigation and compliance, the historical corpus is the actual product. The real waste is sending them *anything* for detection if the latency spikes violate your SLA.
The side-channel is a tacit admission their pipeline can't be trusted for causality, which is more damaging than just being slow. If you can't trust the order, you can't trust any temporal correlation, which breaks far more than just real-time alerts.
>2,500 events per second per agent host
What hardware are you using for the forwarder? That's a serious memory queue if you're holding 90 seconds of that in RAM before spillover. Are you running it on the same host as the agent, or a dedicated logging VM? I'd be worried about disk IO if you move the buffer off-memory.
Also, your example JSON is truncated. Are you sending the full event every time, or can you strip static fields like vendor_name out of the payload to reduce size?
Your batching approach is fundamentally unsuited for that volume with Chronicle's throttling. The `UDM` wrapper adds significant overhead, and each 429 forces a re-queue that destroys sequence integrity.
You need to decouple collection from transmission. Don't write your own forwarder. Use a proven, high-volume buffer like Fluent Bit with a filesystem queue, configured to persist events in strict chronological order to disk before attempting transmission. It handles backoff and retries without scrambling the timeline. Your Go application should emit structured events to Fluent Bit's forward protocol or a Unix socket, not directly to the API.
Also, question the necessity of sending every seccomp check. Pre-filter events at the agent level with a local Bloom filter for repeated, low-severity denials; only forward the first instance and any unique subsequent violations. This reduces your baseline load before the buffer even comes into play.
Ah, the classic "batching to the brittle API" move. I've seen this movie before, and the ending is always a memory leak.
You're losing causality because your in-memory queue is a stack, not a log. When you retry, you're popping the failed batch and pushing it back on top, right? So now your `PROCESS_LAUNCH` from 90 seconds ago is sitting behind a `FILE_ACCESS` from 5 seconds ago. Good luck untangling that in Chronicle.
Even if you fix the order, you're trusting Chronicle's ingestion timestamp for correlation, which is a joke. Their clock skew can be hundreds of milliseconds. You need a monotonic sequence ID embedded in the event *before* it leaves the agent, signed by the agent's key. Otherwise, you're just hoping the timeline looks right.
And that truncated JSON example is worrying. If you're not validating the schema of every event against a known good SBOM of the agent library before batching, you're probably sending malformed nested objects that cause those silent 500s. Chronicle will just drop the whole batch and you'll never know which event blew up.
Trust but verify the checksum.
Batching logic is below. Smaller batches mean more 429s from exceeding the rate limit, not fewer.
```go
type ChronicleBatch struct {
Events []udm.Event
FirstTS int64 // Agent timestamp of oldest event
LastTS int64 // Agent timestamp of newest event
RetryCount int
}
```
I'm stamping `event_time` at the agent, but it gets overwritten by the forwarder's receipt time on retry because Chronicle's ingestion timestamp is trash. That's the causality break.
The real fix is a sequence ID signed by the agent, not timestamp gymnastics.
Assume breach. Then prove you can respond.
Yeah, sequence IDs are the only way to lock it down. But if you're stuck with timestamps for now, you can at least keep your original `event_time` in a custom metadata field before sending. Chronicle won't overwrite that on retry, and your downstream parsers can use it.
>stamping event_time at the agent, but it gets overwritten
This is why I always push agent-signed, monotonic counters. Even a simple `agent_id:seq_num` in the UDM extensions beats timestamp roulette. Your `FirstTS`/`LastTS` struct fields are good for human debugging, but the API will never see them.
One caveat: if you add a signed sequence, you have to validate the signature on ingest or it's just another spoofable field.
You're right that timeline corruption breaks more than just alerts. I had an incident once where we had to reconstruct an attack path manually because the SIEM showed a network connection logged *before* the process that initiated it. The false causality completely derailed our initial response.
It's worse than just being slow - you're basing decisions on fiction. That's why I started embedding a Lamport-like logical clock in my agent events, even though it adds overhead. You can't fix scrambled eggs at the SIEM level.
-- Mike
Oh, that high-volume drop is a classic pain point. I feel you on the retry scramble wrecking causality - once the timeline's cooked, you're basically shipping garbage data.
Your mention of memory exhaustion in the forwarder is the real red flag for me. A custom Go forwarder holding 90 seconds of that firehose in RAM is asking for OOM kills, especially if your backoff logic tries to requeue the whole failed batch. It's not just about order, it's about losing events entirely when the process dies.
I'd look at moving the queue off the forwarder entirely. Something like a local Redis stream with XADD gives you persistence and a strict order that survives forwarder crashes. Your Go code becomes just a producer, and a separate, dumber process handles the Chronicle API with backoff, reading from the stream. It's an extra moving part, but it saves your data when the API gets flaky.
lab.firstname.net
Agree on the principle of moving the queue off the forwarder, but Redis as a stream introduces another point of failure and complexity for the agent host. If you're already memory-pressured, Redis can add to that, and you have to manage persistence settings or risk losing the stream on a reboot anyway.
A simpler, host-local solution is to use a disk-backed FIFO via a named pipe or a simple file in a ring buffer pattern. Your forwarder writes events to it, and a separate, stripped-down sender reads with blocking I/O. The order is preserved by the filesystem, and it survives process death. The memory overhead is just the kernel's pipe buffer, not gigabytes of queued events.
The real trick is making the sender idempotent and resumable, so on a crash it can pick up from the last committed Chronicle ingestion point, which you'd track in a small state file. That avoids re-sending the entire queue.
That volume into Chronicle's vanilla API is going to be painful, full stop. Your causality issue is the real killer, though. I ran into something similar with my own agent's network logs.
I'd push back a bit on the sequence ID being the only fix, at least for now. You can't just embed a counter; you need the whole chain of custody signed, which is a project. A quicker patch is to buffer those events in a separate logging network segment.
I pipe my high-volume logs to a dedicated syslog-ng instance on an isolated logging VLAN first, with disk-backed spooling. That segment handles the queue and order integrity, and *then* a much smaller forwarder batch processes from that spool into Chronicle. Takes the memory pressure off the agent host completely.
segment and conquer
Isolating the logging segment is smart for scaling, but your forwarder's batch logic is still a single point of failure for causality. If it reads from the spool, batches, then 429s and replays that batch, you've scrambled the order *after* the spool. The spool guarantees collection order, not transmission order.
The sender reading from syslog-ng needs to be single-threaded and commit offsets only after successful Chronicle acceptance. Otherwise you're just moving the queue and keeping the problem.
Assume breach. Then prove you can respond.