From 2bc51c5c3215398875c04456a3f3df1c07b830b5 Mon Sep 17 00:00:00 2001 From: Arnab Sen Date: Fri, 3 Sep 2021 22:08:53 +0530 Subject: [tracing] tracepoints to utxocache add, spent and uncache Signed-off-by: Arnab Sen --- contrib/tracing/README.md | 59 +++++++++++++++++++++++ contrib/tracing/log_utxocache_flush.py | 8 ++-- contrib/tracing/log_utxos.bt | 86 ++++++++++++++++++++++++++++++++++ doc/tracing.md | 33 +++++++++++++ src/coins.cpp | 19 ++++++++ src/validation.cpp | 13 +++-- 6 files changed, 208 insertions(+), 10 deletions(-) mode change 100644 => 100755 contrib/tracing/log_utxocache_flush.py create mode 100755 contrib/tracing/log_utxos.bt diff --git a/contrib/tracing/README.md b/contrib/tracing/README.md index 1f93474fa0..b71ce2f34b 100644 --- a/contrib/tracing/README.md +++ b/contrib/tracing/README.md @@ -234,3 +234,62 @@ Histogram of block connection times in milliseconds (ms). [16, 32) 9 | | [32, 64) 4 | | ``` + +### log_utxocache_flush.py + +A BCC Python script to log the cache and index flushes. Based on the +`utxocache:flush` tracepoint. + +```bash +$ python3 contrib/tracing/log_utxocache_flush.py ./src/bitcoind +``` + +``` +Logging utxocache flushes. Ctrl-C to end... +Duration (µs) Mode Coins Count Memory Usage Prune Full Flush +0 PERIODIC 28484 3929.87 kB False False +1 PERIODIC 28485 3930.00 kB False False +0 PERIODIC 28489 3930.51 kB False False +1 PERIODIC 28490 3930.64 kB False False +0 PERIODIC 28491 3930.77 kB False False +0 PERIODIC 28491 3930.77 kB False False +0 PERIODIC 28496 3931.41 kB False False +1 PERIODIC 28496 3931.41 kB False False +0 PERIODIC 28497 3931.54 kB False False +1 PERIODIC 28497 3931.54 kB False False +1 PERIODIC 28499 3931.79 kB False False +. +. +. +53788 ALWAYS 30076 4136.27 kB False False +7463 ALWAYS 0 245.84 kB False False +``` + +### log_utxos.bt + +A `bpftrace` script to log information about the coins that are added, spent, or +uncached from the UTXO set. Based on the `utxocache:add`, `utxocache:spend` and +`utxocache:uncache` tracepoints. + +```bash +$ bpftrace contrib/tracing/log_utxos.bt +``` + +It should produce an output similar to the following. + +```bash +Attaching 4 probes... +OP Outpoint Value Height Coinbase +Added 6ba9ad857e1ef2eb2a2c94f06813c414c7ab273e3d6bd7ad64e000315a887e7c:1 10000 2094512 No +Spent fa7dc4db56637a151f6649d8f26732956d1c5424c82aae400a83d02b2cc2c87b:0 182264897 2094512 No +Added eeb2f099b1af6a2a12e6ddd2eeb16fc5968582241d7f08ba202d28b60ac264c7:0 10000 2094512 No +Added eeb2f099b1af6a2a12e6ddd2eeb16fc5968582241d7f08ba202d28b60ac264c7:1 182254756 2094512 No +Added a0c7f4ec9cccef2d89672a624a4e6c8237a17572efdd4679eea9e9ee70d2db04:0 10072679 2094513 Yes +Spent 25e0df5cc1aeb1b78e6056bf403e5e8b7e41f138060ca0a50a50134df0549a5e:2 540 2094508 No +Spent 42f383c04e09c26a2378272ec33aa0c1bf4883ca5ab739e8b7e06be5a5787d61:1 3848399 2007724 No +Added f85e3b4b89270863a389395cc9a4123e417ab19384cef96533c6649abd6b0561:0 3788399 2094513 No +Added f85e3b4b89270863a389395cc9a4123e417ab19384cef96533c6649abd6b0561:2 540 2094513 No +Spent a05880b8c77971ed0b9f73062c7c4cdb0ff3856ab14cbf8bc481ed571cd34b83:1 5591281046 2094511 No +Added eb689865f7d957938978d6207918748f74e6aa074f47874724327089445b0960:0 5589696005 2094513 No +Added eb689865f7d957938978d6207918748f74e6aa074f47874724327089445b0960:1 1565556 2094513 No +``` diff --git a/contrib/tracing/log_utxocache_flush.py b/contrib/tracing/log_utxocache_flush.py old mode 100644 new mode 100755 index df55b94162..df27dc193a --- a/contrib/tracing/log_utxocache_flush.py +++ b/contrib/tracing/log_utxocache_flush.py @@ -4,8 +4,8 @@ import sys import ctypes from bcc import BPF, USDT -""" Example script to log details about coins flushed by the Bitcoin client -utilizing USDT probes and the flush:flush tracepoint. """ +"""Example logging Bitcoin Core utxo set cache flushes utilizing + the utxocache:flush tracepoint.""" # USAGE: ./contrib/tracing/log_utxocache_flush.py path/to/bitcoind @@ -22,8 +22,10 @@ struct data_t bool is_flush_prune; bool is_full_flush; }; + // BPF perf buffer to push the data to user space. BPF_PERF_OUTPUT(flush); + int trace_flush(struct pt_regs *ctx) { struct data_t data = {}; bpf_usdt_readarg(1, ctx, &data.duration); @@ -45,8 +47,8 @@ FLUSH_MODES = [ ] -# define output data structure class Data(ctypes.Structure): + # define output data structure corresponding to struct data_t _fields_ = [ ("duration", ctypes.c_uint64), ("mode", ctypes.c_uint32), diff --git a/contrib/tracing/log_utxos.bt b/contrib/tracing/log_utxos.bt new file mode 100755 index 0000000000..0d47f3d62b --- /dev/null +++ b/contrib/tracing/log_utxos.bt @@ -0,0 +1,86 @@ +#!/usr/bin/env bpftrace + +/* + + USAGE: + + bpftrace contrib/tracing/log_utxos.bt + + This script requires a 'bitcoind' binary compiled with eBPF support and the + 'utxochache' tracepoints. By default, it's assumed that 'bitcoind' is + located in './src/bitcoind'. This can be modified in the script below. + + NOTE: requires bpftrace v0.12.0 or above. +*/ + +BEGIN +{ + printf("%-7s %-71s %16s %7s %8s\n", + "OP", "Outpoint", "Value", "Height", "Coinbase"); +} + +/* + Attaches to the 'utxocache:add' tracepoint and prints additions to the UTXO set cache. +*/ +usdt:./src/bitcoind:utxocache:add +{ + $txid = arg0; + $index = (uint32)arg1; + $height = (uint32)arg2; + $value = (int64)arg3; + $isCoinbase = arg4; + + printf("Added "); + $p = $txid + 31; + unroll(32) { + $b = *(uint8*)$p; + printf("%02x", $b); + $p-=1; + } + + printf(":%-6d %16ld %7d %s\n", $index, $value, $height, ($isCoinbase ? "Yes" : "No" )); +} + +/* + Attaches to the 'utxocache:spent' tracepoint and prints spents from the UTXO set cache. +*/ +usdt:./src/bitcoind:utxocache:spent +{ + $txid = arg0; + $index = (uint32)arg1; + $height = (uint32)arg2; + $value = (int64)arg3; + $isCoinbase = arg4; + + printf("Spent "); + $p = $txid + 31; + unroll(32) { + $b = *(uint8*)$p; + printf("%02x", $b); + $p-=1; + } + + printf(":%-6d %16ld %7d %s\n", $index, $value, $height, ($isCoinbase ? "Yes" : "No" )); +} + +/* + Attaches to the 'utxocache:uncache' tracepoint and uncache UTXOs from the UTXO set cache. +*/ +usdt:./src/bitcoind:utxocache:uncache +{ + $txid = arg0; + $index = (uint32)arg1; + $height = (uint32)arg2; + $value = (int64)arg3; + $isCoinbase = arg4; + + printf("Uncache "); + $p = $txid + 31; + unroll(32) { + $b = *(uint8*)$p; + printf("%02x", $b); + $p-=1; + } + + printf(":%-6d %16ld %7d %s\n", $index, $value, $height, ($isCoinbase ? "Yes" : "No" )); +} diff --git a/doc/tracing.md b/doc/tracing.md index 4c18179928..5b9ba09c2f 100644 --- a/doc/tracing.md +++ b/doc/tracing.md @@ -124,6 +124,39 @@ Arguments passed: 5. If the flush was pruned as `bool` 6. If it was full flush as `bool` +#### Tracepoint `utxocache:add` + +It is called when a new coin is added to the UTXO cache. + +Arguments passed: +1. Transaction ID (hash) as `pointer to unsigned chars` (i.e. 32 bytes in little-endian) +2. Output index as `uint32` +3. Block height the coin was added to the UTXO-set as `uint32` +4. Value of the coin as `int64` +5. If the coin is a coinbase as `bool` + +#### Tracepoint `utxocache:spent` + +It is called when a coin is spent from the UTXO cache. + +Arguments passed: +1. Transaction ID (hash) as `pointer to unsigned chars` (i.e. 32 bytes in little-endian) +2. Output index as `uint32` +3. Block height the coin was spent, as `uint32` +4. Value of the coin as `int64` +5. If the coin is a coinbase as `bool` + +#### Tracepoint `utxocache:uncache` + +It is called when the UTXO with the given outpoint is removed from the cache. + +Arguments passed: +1. Transaction ID (hash) as `pointer to unsigned chars` (i.e. 32 bytes in little-endian) +2. Output index as `uint32` +3. Block height the coin was uncached, as `uint32` +4. Value of the coin as `int64` +. If the coin is a coinbase as `bool` + ## Adding tracepoints to Bitcoin Core To add a new tracepoint, `#include ` in the compilation unit where diff --git a/src/coins.cpp b/src/coins.cpp index ce0b131de6..daead6055e 100644 --- a/src/coins.cpp +++ b/src/coins.cpp @@ -7,6 +7,7 @@ #include #include #include +#include #include bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; } @@ -95,6 +96,12 @@ void CCoinsViewCache::AddCoin(const COutPoint &outpoint, Coin&& coin, bool possi it->second.coin = std::move(coin); it->second.flags |= CCoinsCacheEntry::DIRTY | (fresh ? CCoinsCacheEntry::FRESH : 0); cachedCoinsUsage += it->second.coin.DynamicMemoryUsage(); + TRACE5(utxocache, add, + outpoint.hash.data(), + (uint32_t)outpoint.n, + (uint32_t)coin.nHeight, + (int64_t)coin.out.nValue, + (bool)coin.IsCoinBase()); } void CCoinsViewCache::EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coin) { @@ -120,6 +127,12 @@ bool CCoinsViewCache::SpendCoin(const COutPoint &outpoint, Coin* moveout) { CCoinsMap::iterator it = FetchCoin(outpoint); if (it == cacheCoins.end()) return false; cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage(); + TRACE5(utxocache, spent, + outpoint.hash.data(), + (uint32_t)outpoint.n, + (uint32_t)it->second.coin.nHeight, + (int64_t)it->second.coin.out.nValue, + (bool)it->second.coin.IsCoinBase()); if (moveout) { *moveout = std::move(it->second.coin); } @@ -231,6 +244,12 @@ void CCoinsViewCache::Uncache(const COutPoint& hash) CCoinsMap::iterator it = cacheCoins.find(hash); if (it != cacheCoins.end() && it->second.flags == 0) { cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage(); + TRACE5(utxocache, uncache, + hash.hash.data(), + (uint32_t)hash.n, + (uint32_t)it->second.coin.nHeight, + (int64_t)it->second.coin.out.nValue, + (bool)it->second.coin.IsCoinBase()); cacheCoins.erase(it); } } diff --git a/src/validation.cpp b/src/validation.cpp index 7a14218b5c..86d2ae7577 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -2102,13 +2102,12 @@ bool CChainState::FlushStateToDisk( full_flush_completed = true; } TRACE6(utxocache, flush, - (int64_t)(GetTimeMicros() - nNow.count()), // in microseconds (µs) - (u_int32_t)mode, - (u_int64_t)coins_count, - (u_int64_t)coins_mem_usage, - (bool)fFlushForPrune, - (bool)fDoFullFlush - ); + (int64_t)(GetTimeMicros() - nNow.count()), // in microseconds (µs) + (u_int32_t)mode, + (u_int64_t)coins_count, + (u_int64_t)coins_mem_usage, + (bool)fFlushForPrune, + (bool)fDoFullFlush); } if (full_flush_completed) { // Update best block in wallet (so we can detect restored wallets). -- cgit v1.2.3