validation: pruning for multiple chainstates

Introduces ChainstateManager::GetPruneRange().

The prune budget is split evenly between the number of chainstates,
however the prune budget may be exceeded if the resulting shares are
beneath `MIN_DISK_SPACE_FOR_BLOCK_FILES`.
This commit is contained in:
James O'Beirne
2019-09-16 16:34:45 -04:00
committed by James O'Beirne
parent 373cf91531
commit 1019c39982
5 changed files with 102 additions and 30 deletions

View File

@@ -257,40 +257,56 @@ void BlockManager::PruneOneBlockFile(const int fileNumber)
m_dirty_fileinfo.insert(fileNumber);
}
void BlockManager::FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight, int chain_tip_height)
void BlockManager::FindFilesToPruneManual(
std::set<int>& setFilesToPrune,
int nManualPruneHeight,
const Chainstate& chain,
ChainstateManager& chainman)
{
assert(IsPruneMode() && nManualPruneHeight > 0);
LOCK2(cs_main, cs_LastBlockFile);
if (chain_tip_height < 0) {
if (chain.m_chain.Height() < 0) {
return;
}
// last block to prune is the lesser of (user-specified height, MIN_BLOCKS_TO_KEEP from the tip)
unsigned int nLastBlockWeCanPrune = std::min((unsigned)nManualPruneHeight, chain_tip_height - MIN_BLOCKS_TO_KEEP);
const auto [min_block_to_prune, last_block_can_prune] = chainman.GetPruneRange(chain, nManualPruneHeight);
int count = 0;
for (int fileNumber = 0; fileNumber < m_last_blockfile; fileNumber++) {
if (m_blockfile_info[fileNumber].nSize == 0 || m_blockfile_info[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
const auto& fileinfo = m_blockfile_info[fileNumber];
if (fileinfo.nSize == 0 || fileinfo.nHeightLast > (unsigned)last_block_can_prune || fileinfo.nHeightFirst < (unsigned)min_block_to_prune) {
continue;
}
PruneOneBlockFile(fileNumber);
setFilesToPrune.insert(fileNumber);
count++;
}
LogPrintf("Prune (Manual): prune_height=%d removed %d blk/rev pairs\n", nLastBlockWeCanPrune, count);
LogPrintf("[%s] Prune (Manual): prune_height=%d removed %d blk/rev pairs\n",
chain.GetRole(), last_block_can_prune, count);
}
void BlockManager::FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight, int chain_tip_height, int prune_height, bool is_ibd)
void BlockManager::FindFilesToPrune(
std::set<int>& setFilesToPrune,
int last_prune,
const Chainstate& chain,
ChainstateManager& chainman)
{
LOCK2(cs_main, cs_LastBlockFile);
if (chain_tip_height < 0 || GetPruneTarget() == 0) {
// Distribute our -prune budget over all chainstates.
const auto target = std::max(
MIN_DISK_SPACE_FOR_BLOCK_FILES, GetPruneTarget() / chainman.GetAll().size());
if (chain.m_chain.Height() < 0 || target == 0) {
return;
}
if ((uint64_t)chain_tip_height <= nPruneAfterHeight) {
if (static_cast<uint64_t>(chain.m_chain.Height()) <= chainman.GetParams().PruneAfterHeight()) {
return;
}
unsigned int nLastBlockWeCanPrune{(unsigned)std::min(prune_height, chain_tip_height - static_cast<int>(MIN_BLOCKS_TO_KEEP))};
const auto [min_block_to_prune, last_block_can_prune] = chainman.GetPruneRange(chain, last_prune);
uint64_t nCurrentUsage = CalculateCurrentUsage();
// We don't check to prune until after we've allocated new space for files
// So we should leave a buffer under our target to account for another allocation
@@ -299,29 +315,31 @@ void BlockManager::FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPr
uint64_t nBytesToPrune;
int count = 0;
if (nCurrentUsage + nBuffer >= GetPruneTarget()) {
if (nCurrentUsage + nBuffer >= target) {
// On a prune event, the chainstate DB is flushed.
// To avoid excessive prune events negating the benefit of high dbcache
// values, we should not prune too rapidly.
// So when pruning in IBD, increase the buffer a bit to avoid a re-prune too soon.
if (is_ibd) {
if (chainman.IsInitialBlockDownload()) {
// Since this is only relevant during IBD, we use a fixed 10%
nBuffer += GetPruneTarget() / 10;
nBuffer += target / 10;
}
for (int fileNumber = 0; fileNumber < m_last_blockfile; fileNumber++) {
nBytesToPrune = m_blockfile_info[fileNumber].nSize + m_blockfile_info[fileNumber].nUndoSize;
const auto& fileinfo = m_blockfile_info[fileNumber];
nBytesToPrune = fileinfo.nSize + fileinfo.nUndoSize;
if (m_blockfile_info[fileNumber].nSize == 0) {
if (fileinfo.nSize == 0) {
continue;
}
if (nCurrentUsage + nBuffer < GetPruneTarget()) { // are we below our target?
if (nCurrentUsage + nBuffer < target) { // are we below our target?
break;
}
// don't prune files that could have a block within MIN_BLOCKS_TO_KEEP of the main chain's tip but keep scanning
if (m_blockfile_info[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
// don't prune files that could have a block that's not within the allowable
// prune range for the chain being pruned.
if (fileinfo.nHeightLast > (unsigned)last_block_can_prune || fileinfo.nHeightFirst < (unsigned)min_block_to_prune) {
continue;
}
@@ -333,10 +351,10 @@ void BlockManager::FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPr
}
}
LogPrint(BCLog::PRUNE, "target=%dMiB actual=%dMiB diff=%dMiB max_prune_height=%d removed %d blk/rev pairs\n",
GetPruneTarget() / 1024 / 1024, nCurrentUsage / 1024 / 1024,
(int64_t(GetPruneTarget()) - int64_t(nCurrentUsage)) / 1024 / 1024,
nLastBlockWeCanPrune, count);
LogPrint(BCLog::PRUNE, "[%s] target=%dMiB actual=%dMiB diff=%dMiB min_height=%d max_prune_height=%d removed %d blk/rev pairs\n",
chain.GetRole(), target / 1024 / 1024, nCurrentUsage / 1024 / 1024,
(int64_t(target) - int64_t(nCurrentUsage)) / 1024 / 1024,
min_block_to_prune, last_block_can_prune, count);
}
void BlockManager::UpdatePruneLock(const std::string& name, const PruneLockInfo& lock_info) {

View File

@@ -36,6 +36,7 @@ class CBlockUndo;
class CChainParams;
class Chainstate;
class ChainstateManager;
enum class ChainstateRole;
struct CCheckpointData;
struct FlatFilePos;
namespace Consensus {
@@ -138,7 +139,11 @@ private:
bool UndoWriteToDisk(const CBlockUndo& blockundo, FlatFilePos& pos, const uint256& hashBlock) const;
/* Calculate the block/rev files to delete based on height specified by user with RPC command pruneblockchain */
void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight, int chain_tip_height);
void FindFilesToPruneManual(
std::set<int>& setFilesToPrune,
int nManualPruneHeight,
const Chainstate& chain,
ChainstateManager& chainman);
/**
* Prune block and undo files (blk???.dat and rev???.dat) so that the disk space used is less than a user-defined target.
@@ -154,8 +159,13 @@ private:
* A db flag records the fact that at least some block files have been pruned.
*
* @param[out] setFilesToPrune The set of file indices that can be unlinked will be returned
* @param last_prune The last height we're able to prune, according to the prune locks
*/
void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight, int chain_tip_height, int prune_height, bool is_ibd);
void FindFilesToPrune(
std::set<int>& setFilesToPrune,
int last_prune,
const Chainstate& chain,
ChainstateManager& chainman);
RecursiveMutex cs_LastBlockFile;
std::vector<CBlockFileInfo> m_blockfile_info;