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Added RPC filter limits, metrics, and better memory management. (#10718)
- Introduced `GetOrCreateGaugeVec` function to manage Prometheus
`GaugeVec` metrics.
- Implemented various subscription filter limits (max logs, max headers,
max transactions, max addresses, and max topics).
- Updated various test files to utilize the new `FiltersConfig` and
added comprehensive tests for the new filter limits.
- Added new flags for subscription filter limits.
- Improved log filtering and event handling with better memory
management and metric tracking.
- Added configuration to handle RPC subscription filter limits.
- Minor typo fixes.
-------
RPC nodes would frequently OOM. Based on metrics and pprof, I observed
high memory utilization in the rpchelper:
```text
File: erigon
Type: inuse_space
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 69696.67MB, 95.37% of 73083.31MB total
Dropped 1081 nodes (cum <= 365.42MB)
Showing top 10 nodes out of 43
flat flat% sum% cum cum%
65925.80MB 90.21% 90.21% 65925.80MB 90.21% github.com/ledgerwatch/erigon/turbo/rpchelper.(*LogsFilterAggregator).distributeLog.func1
1944.80MB 2.66% 92.87% 1944.80MB 2.66% github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddLogs.func1
1055.97MB 1.44% 94.31% 1055.97MB 1.44% github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddPendingTxs.func1
362.04MB 0.5% 94.81% 572.20MB 0.78% github.com/ledgerwatch/erigon/core/state.(*stateObject).GetCommittedState
257.73MB 0.35% 95.16% 587.85MB 0.8% encoding/json.Marshal
57.85MB 0.079% 95.24% 1658.66MB 2.27% github.com/ledgerwatch/erigon/core/vm.(*EVMInterpreter).Run
51.48MB 0.07% 95.31% 2014.50MB 2.76% github.com/ledgerwatch/erigon/rpc.(*handler).handleCallMsg
23.01MB 0.031% 95.34% 1127.21MB 1.54% github.com/ledgerwatch/erigon/core/vm.opCall
11.50MB 0.016% 95.36% 1677.68MB 2.30% github.com/ledgerwatch/erigon/core/vm.(*EVM).call
6.50MB 0.0089% 95.37% 685.70MB 0.94% github.com/ledgerwatch/erigon/turbo/transactions.DoCall
(pprof) list distributeLog.func1
Total: 71.37GB
ROUTINE ======================== github.com/ledgerwatch/erigon/turbo/rpchelper.(*LogsFilterAggregator).distributeLog.func1 in github.com/ledgerwatch/erigon/turbo/rpchelper/logsfilter.go
64.38GB 64.38GB (flat, cum) 90.21% of Total
. . 206: a.logsFilters.Range(func(k LogsSubID, filter *LogsFilter) error {
. . 207: if filter.allAddrs == 0 {
. . 208: _, addrOk := filter.addrs.Get(gointerfaces.ConvertH160toAddress(eventLog.Address))
. . 209: if !addrOk {
. . 210: return nil
. . 211: }
. . 212: }
. . 213: var topics []libcommon.Hash
. . 214: for _, topic := range eventLog.Topics {
27.01GB 27.01GB 215: topics = append(topics, gointerfaces.ConvertH256ToHash(topic))
. . 216: }
. . 217: if filter.allTopics == 0 {
. . 218: if !a.chooseTopics(filter, topics) {
. . 219: return nil
. . 220: }
. . 221: }
37.37GB 37.37GB 222: lg := &types2.Log{
. . 223: Address: gointerfaces.ConvertH160toAddress(eventLog.Address),
. . 224: Topics: topics,
. . 225: Data: eventLog.Data,
. . 226: BlockNumber: eventLog.BlockNumber,
. . 227: TxHash: gointerfaces.ConvertH256ToHash(eventLog.TransactionHash),
(pprof) %
```
- Added Metrics
Implemented metrics to gain visibility into memory utilization.
- Optimized Allocations
Optimized object and slice allocations, resulting in significant
improvements in memory usage.
```text
File: erigon
Type: inuse_space
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 25.92GB, 94.14% of 27.53GB total
Dropped 785 nodes (cum <= 0.14GB)
Showing top 10 nodes out of 70
flat flat% sum% cum cum%
15.37GB 55.82% 55.82% 15.37GB 55.82% github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddLogs.func1
8.15GB 29.60% 85.42% 8.15GB 29.60% github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddPendingTxs.func1
0.64GB 2.33% 87.75% 1GB 3.65% github.com/ledgerwatch/erigon/turbo/rpchelper.(*LogsFilterAggregator).distributeLog
0.50GB 1.82% 89.57% 0.65GB 2.35% github.com/ledgerwatch/erigon/core/state.(*stateObject).GetCommittedState
0.36GB 1.32% 90.89% 0.36GB 1.32% github.com/ledgerwatch/erigon/turbo/rpchelper.(*LogsFilterAggregator).distributeLog.func1
0.31GB 1.12% 92.01% 0.31GB 1.12% bytes.growSlice
0.30GB 1.08% 93.09% 0.30GB 1.08% github.com/ledgerwatch/erigon/core/vm.(*Memory).Resize (inline)
0.15GB 0.56% 93.65% 0.35GB 1.27% github.com/ledgerwatch/erigon/core/state.(*IntraBlockState).AddSlotToAccessList
0.07GB 0.24% 93.90% 0.23GB 0.84% github.com/ledgerwatch/erigon/core/types.codecSelfer2.decLogs
0.07GB 0.24% 94.14% 1.58GB 5.75% github.com/ledgerwatch/erigon/core/vm.(*EVMInterpreter).Run
(pprof) list AddLogs.func1
Total: 27.53GB
ROUTINE ======================== github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddLogs.func1 in github.com/ledgerwatch/erigon/turbo/rpchelper/filters.go
15.37GB 15.37GB (flat, cum) 55.82% of Total
. . 644: ff.logsStores.DoAndStore(id, func(st []*types.Log, ok bool) []*types.Log {
. . 645: if !ok {
. . 646: st = make([]*types.Log, 0)
. . 647: }
15.37GB 15.37GB 648: st = append(st, logs)
. . 649: return st
. . 650: })
. . 651:}
. . 652:
. . 653:// ReadLogs reads logs from the store associated with the given subscription ID.
(pprof) list AddPendingTxs.func1
Total: 27.53GB
ROUTINE ======================== github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddPendingTxs.func1 in github.com/ledgerwatch/erigon/turbo/rpchelper/filters.go
8.15GB 8.15GB (flat, cum) 29.60% of Total
. . 686: ff.pendingTxsStores.DoAndStore(id, func(st [][]types.Transaction, ok bool) [][]types.Transaction {
. . 687: if !ok {
. . 688: st = make([][]types.Transaction, 0)
. . 689: }
8.15GB 8.15GB 690: st = append(st, txs)
. . 691: return st
. . 692: })
. . 693:}
. . 694:
. . 695:// ReadPendingTxs reads pending transactions from the store associated with the given subscription ID.
(pprof) %
```
- Identified unbound slices that could grow indefinitely, leading to
memory leaks. This issue occurs if subscribers do not request updates
using their subscription ID, especially when behind a load balancer that
does not pin clients to RPC nodes.
1. Architecture Design Changes
- Implement architectural changes to pin clients to RPC Nodes ensuring
subscribers that request updates using their subscription IDs will hit
the same node, which does clean up the objecs on each request.
- Reason for not choosing: This still relies on clients with
subscriptions to request updates and if they never do and do not call
the unsubscribe function it's an unbound memory leak. The RPC node
operator has no control over the behavior of the clients.
2. Implementing Timeouts
- Introduce timeouts for subscriptions to automatically clean up
unresponsive or inactive subscriptions.
- Reason for not choosing: Implementing timeouts would inadvertently
stop websocket subscriptions due to the current design of the code,
leading to a potential loss of data for active users. This solution
would be good but requires a lot more work.
3. Configurable Limits (Chosen Solution)
- Set configurable limits for various subscription parameters (e.g.,
logs, headers, transactions, addresses, topics) to manage memory
utilization effectively.
- Reason for choosing: This approach provides flexibility to RPC node
operators to configure limits as per their requirements. The default
behavior remains unchanged, making it a non-breaking change.
Additionally, it ensures current data is always available by pruning the
oldest data first.
```bash
--rpc.subscription.filters.maxlogs=60
--rpc.subscription.filters.maxheaders=60
--rpc.subscription.filters.maxtxs=10_000
--rpc.subscription.filters.maxaddresses=1_000
--rpc.subscription.filters.maxtopics=1_000
```
```text
File: erigon
Type: inuse_space
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 1146.51MB, 89.28% of 1284.17MB total
Dropped 403 nodes (cum <= 6.42MB)
Showing top 10 nodes out of 124
flat flat% sum% cum cum%
923.64MB 71.92% 71.92% 923.64MB 71.92% github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddPendingTxs.func1
54.59MB 4.25% 76.18% 54.59MB 4.25% github.com/ledgerwatch/erigon/rlp.(*Stream).Bytes
38.21MB 2.98% 79.15% 38.21MB 2.98% bytes.growSlice
29.34MB 2.28% 81.44% 29.34MB 2.28% github.com/ledgerwatch/erigon/p2p/rlpx.growslice
26.44MB 2.06% 83.49% 34.16MB 2.66% compress/flate.NewWriter
18.66MB 1.45% 84.95% 21.16MB 1.65% github.com/ledgerwatch/erigon/core/state.(*stateObject).GetCommittedState
17.50MB 1.36% 86.31% 64.58MB 5.03% github.com/ledgerwatch/erigon/core/types.(*DynamicFeeTransaction).DecodeRLP
15MB 1.17% 87.48% 82.08MB 6.39% github.com/ledgerwatch/erigon/core/types.UnmarshalTransactionFromBinary
13.58MB 1.06% 88.54% 13.58MB 1.06% github.com/ledgerwatch/erigon/turbo/stages/headerdownload.(*HeaderDownload).addHeaderAsLink
9.55MB 0.74% 89.28% 9.55MB 0.74% github.com/ledgerwatch/erigon/turbo/rpchelper.newChanSub[...]
(pprof) list AddPendingTxs.func1
Total: 1.25GB
ROUTINE ======================== github.com/ledgerwatch/erigon/turbo/rpchelper.(*Filters).AddPendingTxs.func1 in github.com/ledgerwatch/erigon/turbo/rpchelper/filters.go
923.64MB 923.64MB (flat, cum) 71.92% of Total
. . 698: ff.pendingTxsStores.DoAndStore(id, func(st [][]types.Transaction, ok bool) [][]types.Transaction {
. . 699: if !ok {
. . 700: st = make([][]types.Transaction, 0)
. . 701: }
. . 702:
. . 703: // Calculate the total number of transactions in st
. . 704: totalTxs := 0
. . 705: for _, txBatch := range st {
. . 706: totalTxs += len(txBatch)
. . 707: }
. . 708:
. . 709: maxTxs := ff.config.RpcSubscriptionFiltersMaxTxs
. . 710: // If adding the new transactions would exceed maxTxs, remove oldest transactions
. . 711: if maxTxs > 0 && totalTxs+len(txs) > maxTxs {
. . 712: // Flatten st to a single slice
918.69MB 918.69MB 713: flatSt := make([]types.Transaction, 0, totalTxs)
. . 714: for _, txBatch := range st {
. . 715: flatSt = append(flatSt, txBatch...)
. . 716: }
. . 717:
. . 718: // Remove the oldest transactions to make space for new ones
. . 719: if len(flatSt)+len(txs) > maxTxs {
. . 720: flatSt = flatSt[len(flatSt)+len(txs)-maxTxs:]
. . 721: }
. . 722:
. . 723: // Convert flatSt back to [][]types.Transaction with a single batch
. . 724: st = [][]types.Transaction{flatSt}
. . 725: }
. . 726:
. . 727: // Append the new transactions as a new batch
5.95MB 4.95MB 728: st = append(st, txs)
. . 729: return st
. . 730: })
. . 731:}
. . 732:
. . 733:// ReadPendingTxs reads pending transactions from the store associated with the given subscription ID.
```
With these changes, the memory utilization has significantly improved,
and the system is now more stable and predictable.
-----
<img width="1567" alt="image"
src="https://github.com/ledgerwatch/erigon/assets/787344/264c9757-93cf-4be8-9883-5ca3187acd73">
Blue line indicates a deployment
Sharp drop of green line is an OOM- Loading branch information
