DAOS-18541 rebuild: accumulate more OIDs per migrate RPC to reduce RPC count#17704
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wangshilong wants to merge 1 commit intomasterfrom
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DAOS-18541 rebuild: accumulate more OIDs per migrate RPC to reduce RPC count#17704wangshilong wants to merge 1 commit intomasterfrom
wangshilong wants to merge 1 commit intomasterfrom
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Fix yield-count accounting in the scanner: rebuild_object() is a pure in-memory btree insert and does not need to contribute yield pressure. A send-side batching policy is also introduced: the send ULT defers flushing until at least REBUILD_SEND_BATCH_MIN OIDs are queued or REBUILD_SEND_BATCH_TIMEOUT_SEC seconds have elapsed, preventing a flood of small migrate RPCs when the scanner runs faster than the sender — particularly under reintegration workloads. Signed-off-by: Wang Shilong <shilong.wang@hpe.com>
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Ticket title is 'Rebuild stuck on Bear cluster' |
wangshilong
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wangshilong
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gnailzenh
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Mar 15, 2026
| if (rc) | ||
| D_GOTO(out, rc); | ||
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| arg->yield_cnt--; |
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I thought rebuild_object() is a btree_insert()(it is a pure memory operations) probably ok not acccounting for yield, could add it back.
| if (dbtree_is_empty(tls->rebuild_tree_hdl)) { | ||
| tree_empty = dbtree_is_empty(tls->rebuild_tree_hdl); | ||
| scan_done = tls->rebuild_pool_scan_done; | ||
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how about "now = daos_gettime_coarse()" at here
| if (tree_empty) { | ||
| /* Reset wait clock and yield to let scan make progress. */ | ||
| tls->rebuild_send_wait_start = daos_gettime_coarse(); | ||
| dss_sleep(0); |
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I'd suggest to change this to dss_sleep(10) as well, make it consistent with the code below
| /* Minimum pending objects before the send ULT flushes a batch (25% of max). */ | ||
| #define REBUILD_SEND_BATCH_MIN (REBUILD_SEND_LIMIT / 4) | ||
| /* Maximum seconds to wait for a batch to fill before flushing anyway. */ | ||
| #define REBUILD_SEND_BATCH_TIMEOUT_SEC 2 |
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probably change this to 1 seconds is OK
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Fix yield-count accounting in the scanner: rebuild_object() is a pure in-memory btree insert and does not need to contribute yield pressure. A send-side batching policy is also introduced: the send ULT defers flushing until at least REBUILD_SEND_BATCH_MIN OIDs are queued or REBUILD_SEND_BATCH_TIMEOUT_SEC seconds have elapsed.
Without batching, a fast scanner floods the destination rank with many small RPCs, exhausting IB receive buffers and triggering timeouts. This is especially severe during reintegration, where all OIDs are concentrated on a single target rank.
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