The following figure shows the memory allocation for each unit of a HiRDB/Parallel Server.
Figure 15-2 Memory allocation for each unit of a HiRDB/Parallel Server
The following table lists details about the shared memory for each unit of a HiRDB Parallel Server.
Table 15-6 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 (0-2,000) x 2 |
Maximum value per segment | See Table 15-7 Size of memory required for each unit of a HiRDB/Parallel Server. It may not be possible to allocate this size depending on the OS environment. | Divide the segment by the SHMMAX operand value. It may not be possible to allocate this size depending on the OS environment. | See Table 15-7 Size of memory required for each unit of a HiRDB/Parallel Server. It may not be possible to allocate this size depending on the OS environment. | See Table 15-7 Size of memory required for each unit of a HiRDB/Parallel Server. It may not be possible to allocate this size depending on the OS environment. | See Table 15-7 Size of memory required for each unit of a HiRDB/Parallel Server. It may not be possible to allocate this size depending on the OS environment. |
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). | -- | -- |