Disk Throughput Requirements

The following table describes the disk throughput requirements in OCNADD:

Table 3-6 Disk Throughput Requirements

Avg Size (in Bytes) Rate RF (Kafka Replication Factor) Topic (NF+MAIN) Consumer Feed Total Write Throughput (MB/s) Total Read Throughput (MB/s) No. of Broker Per Broker Write Throughput (MB/s) Per Broker Read Throughput (MB/s) Total per Broker Throughput (MB/s) with 10% buffer Total Disk Throughput (MB/s) for the Cluster with 10% Buffer
1941 39000 1 2 1 145 145 3 54 54 108 324
1941 39000 2 2 1 289 289 3 106 106 212 636
3769 39000 1 2 1 281 281 3 104 104 208 624
3769 39000 2 2 1 561 561 3 206 206 412 1236

Note:

  • The average size of OCNADD Ingress message captured in the table includes the size of metadata list + header list of original 5G HTTP2 header frame + 5G-SBI-Message.
  • For OCNADD 22.0.0, it is recommended to set the Replication Factor (RF) value to 1 with the assumption that the underlying storage provides data redundancy.
The disk throughput calculations are as follows:

Writes: W * RF * T    
Reads: ((RF*T)+C- 1) * W    
Disk Throughput (Write + Read): (W * RF *T) + (L * W)
W -> MB/sec of data that will be written                
RF -> Replication factor                
T   -> No of topics to which data copied. As of now, each message will be copied into two topics.                
C   -> Number of consumer groups, that is the number of readers for each write                
L   -> (RF*T) + C -1

Average Message in Table:

Average Message Size= (a1b1+a2b2+..+a(n)b(n))/(a1+a2+..+a(n))  
a1   -> SCP MPS    
b1   -> SCP message size    
a2   -> NRF MPS    
b2   -> NRF message size    
a(n) -> NF(n) MPS    
b(n) -> NF(n) message size    

Example:

Average message size for row 1 = ((1624*30000)+(3000*9000))/(30000+9000) = 1941 Bytes (approx)

Average message size for row 4 = ((4000*30000)+(3000*9000))/(30000+9000) = 3769 Bytes (approx)

The following table describes the disk throughput for SCP and NRF:

Table 3-7 SCP and NRF Disk Throughput

SCP Message NRF Message RF (Kafka Replication Factor) Topic (NF+MAIN) Consumer Feed Total Write Throughput (MB/s) Total Read Throughput (MB/s) No.of Broker Per Broker Write Throughput (MB/s) Per Broker Read Throughput (MB/s) Total per Broker Throughput (MB/s) with 10% buffer Total Disk Throughput (MB/s) for Cluster with 10% Buffer
Avg Size (in Bytes) Rate Avg Size (in Bytes) Rate
1624 30000 3000 9000 1 2 1 145 145 3 54 54 108 324
1624 30000 3000 9000 2 2 1 289 289 3 106 106 212 636
4000 30000 3000 9000 1 2 1 281 281 3 104 104 208 624
4000 30000 3000 9000 2 2 1 561 561 3 206 206 412 1236