Figure 16-2 shows the memory allocation for each unit of a HiRDB/Parallel Server.
Figure 16-2 Memory allocation for each unit of a HiRDB/Parallel Server
Table 16-6 provides the details of the shared memories for a unit of a HiRDB/Parallel Server.
Table 16-6 HiRDB/Parallel Server shared memory details per unit
Item | Type of shared memory | ||||
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Unit controller shared memory | Global buffer shared memory | Utility shared memory | Security audit information buffer shared memory | Inter-process memory communication shared memory | |
Purpose | System control | Global buffers | Communication between the unit controller and utilities | Security audit information buffer | Client-server inter-process communication |
Processes | All HiRDB processes | Back-end servers, dictionary servers | Utility processes | Front-end servers | Front-end servers, client processes |
Number of segments | 1 |
| 1 | 1 | Number of clients connected using the PDIPC=MEMORY environment variable (0-2000) ![]() |
Maximum value per segment | See Table 16-7 Size of memory required for each unit of a HiRDB/Parallel Server. Value of the shmmax operating parameter must be equal to or greater than the calculation value. | Divide the segment by the SHMMAX operand value. Value of the shmmax operating parameter must be equal to or greater than the SHMMAX operand value. | See Table 16-7 Size of memory required for each unit of a HiRDB/Parallel Server. Value of the shmmax operating parameter must be equal to or greater than the calculation value. | See Table 16-7 Size of memory required for each unit of a HiRDB/Parallel Server. Value of the shmmax operating parameter must be equal to or greater than the calculation value. | See Table 16-7 Size of memory required for each unit of a HiRDB/Parallel Server. Value of the shmmax operating parameter must be equal to or greater than the calculation value. |
Allocation conditions | None | There must be a global buffer definition | Specify pd_utl_exec_mode=1 | Specify the pd_aud_file_name operand as the HiRDB file system area name for the audit trail. | There are clients connected using the PDIPC=MEMORY environment variable |
Creation timing | At unit activation (including standby unit activation when the rapid system switchover facility is used) |
| When utilities are executed | When a front-end server starts up | When client and server are connected |
Deletion timing | At next unit activation (including standby unit activation when the rapid system switchover facility is used) |
| 10 minutes after the utility terminates | When a front-end server quits | When client and server are disconnected |
Indication by pdls -d mem | Indicated | Indicated | Indicated | Indicated | Not indicated |
SHM-OWNER of pdls -d mem | MANAGER | Server name | UTILITY | AUDDEF | Not indicated |
Related operands |
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Remarks | ![]() | ![]() | Can be created only when pd_utl_exec_mode=1 (when pd_utl_exec_mode=0, the relevant space is allocated in the unit controller shared memory). | ![]() | ![]() |