Commit 1c8219c5 authored by tomas@whalegate.ndb.mysql.com's avatar tomas@whalegate.ndb.mysql.com
Browse files

bug#29099 - slow backup for disk data 

- implement read ahead during disk data scan
parent 2606bb1c

storage/ndb/src/kernel/blocks/dbtup/Dbtup.hpp

+3 −0
Original line number Diff line number Diff line
@@ -2620,6 +2620,9 @@ private: 
  Uint32 cnoOfAllocatedPages;

  Uint32 m_max_allocate_pages;



  /* read ahead in pages during disk order scan */

  Uint32 m_max_page_read_ahead;

  

  Tablerec *tablerec;

  Uint32 cnoOfTablerec;

storage/ndb/src/kernel/blocks/dbtup/DbtupGen.cpp

+12 −0
Original line number Diff line number Diff line
@@ -347,6 +347,18 @@ void Dbtup::execREAD_CONFIG_REQ(Signal* signal) 
  ndbrequire(!ndb_mgm_get_int_parameter(p, CFG_DB_BATCH_SIZE, &nScanBatch));

  c_scanLockPool.setSize(nScanOp * nScanBatch);





  /* read ahead for disk scan can not be more that disk page buffer */

  {

    Uint64 tmp = 64*1024*1024;

    ndb_mgm_get_int64_parameter(p, CFG_DB_DISK_PAGE_BUFFER_MEMORY, &tmp);

    m_max_page_read_ahead = (tmp  + GLOBAL_PAGE_SIZE - 1) / GLOBAL_PAGE_SIZE; // in pages

    // never read ahead more than 32 pages

    if (m_max_page_read_ahead > 32)

      m_max_page_read_ahead = 32;

  }





  ScanOpPtr lcp;

  ndbrequire(c_scanOpPool.seize(lcp));

  new (lcp.p) ScanOp();

storage/ndb/src/kernel/blocks/dbtup/DbtupScan.cpp

+63 −1
Original line number Diff line number Diff line
@@ -686,13 +686,74 @@ Dbtup::scanNext(Signal* signal, ScanOpPtr scanPtr) 
            // move to next extent

            jam();

            pos.m_extent_info_ptr_i = ext_ptr.i;

            Extent_info* ext = c_extent_pool.getPtr(pos.m_extent_info_ptr_i);

            ext = c_extent_pool.getPtr(pos.m_extent_info_ptr_i);

            key.m_file_no = ext->m_key.m_file_no;

            key.m_page_no = ext->m_first_page_no;

          }

        }

        key.m_page_idx = 0;

        pos.m_get = ScanPos::Get_page_dd;

        /*

          read ahead for scan in disk order

          do read ahead every 8:th page

        */

        if ((bits & ScanOp::SCAN_DD) &&

            (((key.m_page_no - ext->m_first_page_no) & 7) == 0))

        {

          jam();

          // initialize PGMAN request

          Page_cache_client::Request preq;

          preq.m_page = pos.m_key;

          preq.m_callback = TheNULLCallback;



          // set maximum read ahead

          Uint32 read_ahead = m_max_page_read_ahead;



          while (true)

          {

            // prepare page read ahead in current extent

            Uint32 page_no = preq.m_page.m_page_no;

            Uint32 page_no_limit = page_no + read_ahead;

            Uint32 limit = ext->m_first_page_no + alloc.m_extent_size;

            if (page_no_limit > limit)

            {

              jam();

              // read ahead crosses extent, set limit for this extent

              read_ahead = page_no_limit - limit;

              page_no_limit = limit;

              // and make sure we only read one extra extent next time around

              if (read_ahead > alloc.m_extent_size)

                read_ahead = alloc.m_extent_size;

            }

            else

            {

              jam();

              read_ahead = 0; // no more to read ahead after this

            }

            // do read ahead pages for this extent

            while (page_no < page_no_limit)

            {

              // page request to PGMAN

              jam();

              preq.m_page.m_page_no = page_no;

              int flags = 0;

              // ignore result

              m_pgman.get_page(signal, preq, flags);

              jamEntry();

              page_no++;

            }

            if (!read_ahead || !list.next(ext_ptr))

            {

              // no more extents after this or read ahead done

              jam();

              break;

            }

            // move to next extent and initialize PGMAN request accordingly

            Extent_info* ext = c_extent_pool.getPtr(ext_ptr.i);

            preq.m_page.m_file_no = ext->m_key.m_file_no;

            preq.m_page.m_page_no = ext->m_first_page_no;

          }

        } // if ScanOp::SCAN_DD read ahead

      }

      /*FALLTHRU*/

    case ScanPos::Get_page_dd:
@@ -725,6 +786,7 @@ Dbtup::scanNext(Signal* signal, ScanOpPtr scanPtr) 
          safe_cast(&Dbtup::disk_page_tup_scan_callback);

        int flags = 0;

        int res = m_pgman.get_page(signal, preq, flags);

        jamEntry();

        if (res == 0) {

          jam();

          // request queued

storage/ndb/src/kernel/blocks/pgman.cpp

+2 −2
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ Pgman::execREAD_CONFIG_REQ(Signal* signal) 
  

  if (page_buffer > 0)

  {

    page_buffer /= GLOBAL_PAGE_SIZE; // in pages

    page_buffer = (page_buffer + GLOBAL_PAGE_SIZE - 1) / GLOBAL_PAGE_SIZE; // in pages

    m_param.m_max_pages = page_buffer;

    m_page_entry_pool.setSize(m_param.m_lirs_stack_mult * page_buffer);

    m_param.m_max_hot_pages = (page_buffer * 9) / 10;
@@ -144,7 +144,7 @@ Pgman::Param::Param() : 
  m_lirs_stack_mult(10),

  m_max_hot_pages(56),

  m_max_loop_count(256),

  m_max_io_waits(64),

  m_max_io_waits(256),

  m_stats_loop_delay(1000),

  m_cleanup_loop_delay(200),

  m_lcp_loop_delay(0)

storage/ndb/src/kernel/vm/SimulatedBlock.cpp

+5 −0
Original line number Diff line number Diff line
@@ -1658,6 +1658,11 @@ SimulatedBlock::sendFragmentedSignal(NodeReceiverGroup rg, 
}



SimulatedBlock::Callback SimulatedBlock::TheEmptyCallback = {0, 0};

void

SimulatedBlock::TheNULLCallbackFunction(class Signal*, Uint32, Uint32)

{ abort(); /* should never be called */ }

SimulatedBlock::Callback SimulatedBlock::TheNULLCallback =

{ &SimulatedBlock::TheNULLCallbackFunction, 0 };



void

SimulatedBlock::sendFragmentedSignal(BlockReference ref,