MDEV-38595: Simplify InnoDB doublewrite buffer creation#4554
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Thirunarayanan
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Jan 19, 2026
buf_dblwr_t::create(): Create the doublewrite buffer in a single atomic mini-transaction. Do not write any log records for initializing any doublewrite buffer pages, in order to avoid recovery failure with innodb_log_archive=ON starting from the very beginning. The mtr.commit() in buf_dblwr_t::create() was observed to comprise 295 mtr_t::m_memo entries: 1 entry for the fil_system.sys_space and the rest split between page 5 (TRX_SYS) and page 0 (allocation metadata). We are nowhere near the sux_lock::RECURSIVE_MAX limit of 65535 per page descriptor. Reviewed by: Thirunarayanan Balathandayuthapani Tested by: Saahil Alam
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buf_dblwr_t::create(): Create the doublewrite buffer in a single atomic mini-transaction. Do not write any log records for initializing any doublewrite buffer pages, in order to avoid recovery failure withinnodb_log_archive=ON(#4405) starting from the very beginning.The
mtr.commit()inbuf_dblwr_t::create()was observed to comprise 295mtr_t::m_memoentries: 1 entry for thefil_system.sys_spaceand the rest split between page 5 (TRX_SYS) and page 0 (allocation metadata). We are nowhere near thesux_lock::RECURSIVE_MAXlimit of 65535 per page descriptor.