github.com/KYVENetwork/cometbft/v38@v38.0.3/docs/qa/CometBFT-QA-37.md (about)

     1  ---
     2  order: 1
     3  parent:
     4    title: CometBFT QA Results v0.37.x
     5    description: This is a report on the results obtained when running CometBFT v0.37.x on testnets
     6    order: 5
     7  ---
     8  
     9  # CometBFT QA Results v0.37.x
    10  
    11  This iteration of the QA was run on CometBFT `v0.37.0-alpha3`, the first `v0.37.x` version from the CometBFT repository.
    12  
    13  The changes with respect to the baseline, `TM v0.37.x` as of Oct 12, 2022 (Commit: 1cf9d8e276afe8595cba960b51cd056514965fd1), include the rebranding of our fork of Tendermint Core to CometBFT and several improvements, described in the CometBFT [CHANGELOG](https://github.com/KYVENetwork/cometbft/v38/blob/v0.37.0-alpha.3/CHANGELOG.md).
    14  
    15  ## Testbed
    16  
    17  As in other iterations of our QA process, we have used a 200-node network as testbed, plus nodes to introduce load and collect metrics.
    18  
    19  ### Saturation point
    20  
    21  As in previous iterations, in our QA experiments, the system is subjected to a load slightly under a saturation point.
    22  The method to identify the saturation point is explained [here](TMCore-QA-34.md#finding-the-saturation-point) and its application to the baseline is described [here](TMCore-QA-37.md#finding-the-saturation-point).
    23  We use the same saturation point, that is, `c`, the number of connections created by the load runner process to the target node, is 2 and `r`, the rate or number of transactions issued per second, is 200.
    24  
    25  ## Examining latencies
    26  
    27  The following figure plots six experiments carried out with the network.
    28  Unique identifiers, UUID, for each execution are presented on top of each graph.
    29  
    30  ![latencies](img37/200nodes_cmt037/all_experiments.png)
    31  
    32  We can see that the latencies follow comparable patterns across all experiments.
    33  Therefore, in the following sections we will only present the results for one representative run, chosen randomly, with UUID starting with `75cb89a8`.
    34  
    35  ![latencies](img37/200nodes_cmt037/e_75cb89a8-f876-4698-82f3-8aaab0b361af.png).
    36  
    37  For reference, the following figure shows the latencies of different configuration of the baseline.
    38  `c=02 r=200` corresponds to the same configuration as in this experiment.
    39  
    40  ![all-latencies](img37/200nodes_tm037/v037_200node_latencies.png)
    41  
    42  As can be seen, latencies are similar.
    43  
    44  ## Prometheus Metrics on the Chosen Experiment
    45  
    46  This section further examines key metrics for this experiment extracted from Prometheus data regarding the chosen experiment.
    47  
    48  ### Mempool Size
    49  
    50  The mempool size, a count of the number of transactions in the mempool, was shown to be stable and homogeneous at all full nodes.
    51  It did not exhibit any unconstrained growth.
    52  The plot below shows the evolution over time of the cumulative number of transactions inside all full nodes' mempools at a given time.
    53  
    54  ![mempoool-cumulative](img37/200nodes_cmt037/mempool_size.png)
    55  
    56  The following picture shows the evolution of the average mempool size over all full nodes, which mostly oscilates between 1500 and 2000 outstanding transactions.
    57  
    58  ![mempool-avg](img37/200nodes_cmt037/avg_mempool_size.png)
    59  
    60  The peaks observed coincide with the moments when some nodes reached round 1 of consensus (see below).
    61  
    62  
    63  The behavior is similar to the observed in the baseline, presented next.
    64  
    65  ![mempool-cumulative-baseline](img37/200nodes_tm037/mempool_size.png)
    66  
    67  ![mempool-avg-baseline](img37/200nodes_tm037/avg_mempool_size.png)
    68  
    69  
    70  ### Peers
    71  
    72  The number of peers was stable at all nodes.
    73  It was higher for the seed nodes (around 140) than for the rest (between 16 and 78).
    74  The red dashed line denotes the average value.
    75  
    76  ![peers](img37/200nodes_cmt037/peers.png)
    77  
    78  Just as in the baseline, shown next, the fact that non-seed nodes reach more than 50 peers is due to [\#9548].
    79  
    80  ![peers](img37/200nodes_tm037/peers.png)
    81  
    82  
    83  ### Consensus Rounds per Height
    84  
    85  Most heights took just one round, that is, round 0, but some nodes needed to advance to round 1 and eventually round 2.
    86  
    87  ![rounds](img37/200nodes_cmt037/rounds.png)
    88  
    89  The following specific run of the baseline presented better results, only requiring up to round 1, but reaching higher rounds is not uncommon in the corresponding software version.
    90  
    91  ![rounds](img37/200nodes_tm037/rounds.png)
    92  
    93  ### Blocks Produced per Minute, Transactions Processed per Minute
    94  
    95  The following plot shows the rate in which blocks were created, from the point of view of each node.
    96  That is, it shows when each node learned that a new block had been agreed upon.
    97  
    98  ![heights](img37/200nodes_cmt037/block_rate.png)
    99  
   100  For most of the time when load was being applied to the system, most of the nodes stayed around 20 to 25 blocks/minute.
   101  
   102  The spike to more than 175 blocks/minute is due to a slow node catching up.
   103  
   104  The collective spike on the right of the graph marks the end of the load injection, when blocks become smaller (empty) and impose less strain on the network.
   105  This behavior is reflected in the following graph, which shows the number of transactions processed per minute.
   106  
   107  ![total-txs](img37/200nodes_cmt037/total_txs_rate.png)
   108  
   109  The baseline experienced a similar behavior, shown in the following two graphs.
   110  The first depicts the block rate.
   111  
   112  ![heights-baseline](img37/200nodes_tm037/block_rate_regular.png)
   113  
   114  The second plots the transaction rate.
   115  
   116  ![total-txs-baseline](img37/200nodes_tm037/total_txs_rate_regular.png)
   117  
   118  ### Memory Resident Set Size
   119  
   120  The Resident Set Size of all monitored processes is plotted below, with maximum memory usage of 2GB.
   121  
   122  ![rss](img37/200nodes_cmt037/memory.png)
   123  
   124  A similar behavior was shown in the baseline, presented next.
   125  
   126  ![rss](img37/200nodes_tm037/memory.png)
   127  
   128  The memory of all processes went down as the load as removed, showing no signs of unconstrained growth.
   129  
   130  
   131  #### CPU utilization
   132  
   133  The best metric from Prometheus to gauge CPU utilization in a Unix machine is `load1`,
   134  as it usually appears in the
   135  [output of `top`](https://www.digitalocean.com/community/tutorials/load-average-in-linux).
   136  
   137  It is contained below 5 on most nodes, as seen in the following graph.
   138  
   139  ![load1](img37/200nodes_cmt037/cpu.png)
   140  
   141  A similar behavior was seen in the baseline.
   142  
   143  ![load1-baseline](img37/200nodes_tm037/cpu.png)
   144  
   145  
   146  ## Test Results
   147  
   148  The comparison against the baseline results show that both scenarios had similar numbers and are therefore equivalent.
   149  
   150  A conclusion of these tests is shown in the following table, along with the commit versions used in the experiments.
   151  
   152  | Scenario | Date | Version | Result |
   153  |--|--|--|--|
   154  |CometBFT | 2023-02-14 | v0.37.0-alpha3 (bef9a830e7ea7da30fa48f2cc236b1f465cc5833) | Pass
   155  
   156  
   157  [\#9548]: https://github.com/tendermint/tendermint/issues/9548