Why does a first "LoadDocument" take 5000ms+

[xinix00]

Hi,

I was creating a system to run jobs, which makes a new process for each. Works fine, 100ms to boot up, but when I query my first document:

  0: Document: 5320.1797ms: Configs/Currency

it takes over 5000ms, this is every time (without an exception), also when I query a non existing document. Any way to speed this up? after initial connection it is fast:

  0: Document: 20.0076ms: currencies/Base/2

[ayende]

I assume that the database is already loaded when this happens?
If you run the process twice, within a minute or so, do you still see this behavior?

Are you generating the certificate somehow? Fetching it remotely?

what client are you using? Is the server nearby or remote?

[derekdhaas]

In this example a cluster of 3, latency at most 10ms. Database is already loaded. 7.0.2. Certificate is used, static one available on the host.

I will check what it does after a minute.

[xinix00]

=== Iteration 1 at 16:06:33 ===
LoadAsync took: 5542ms
Waiting 2 minutes...

=== Iteration 2 at 16:08:39 ===
LoadAsync took: 5826ms
Waiting 2 minutes...

Which is just a simple DocumentStore, LoadAsync("not-existing-id")

[xinix00]

Ok just for people who use .local, with MacOS:

Add ipv4 and ipv6 if you route it yourself. I'm tunneling (kubectl) it to my PC, and RavenDB wants hostnames, so I added ipv4 only (to 127.0.0.1). MacOS (and dotnet) is also requesting an IPv6, which fails at /etc/hosts, so goes through mDNS which times out after 5 seconds. So add ::1 to the hostnames in /etc/hosts

If you (like me) also run some services on MacOS, which do need to resolve IPv4 but not v6, brew install coredns:

sudo tee /opt/homebrew/etc/coredns/Corefile > /dev/null <<EOF
svc.cluster.local {
template IN A {
match .*.svc.cluster.local.
answer "{{ .Name }} 60 IN A 127.0.0.1"
}

template IN AAAA {
match .*.svc.cluster.local.
rcode NOERROR
}

forward . 127.0.0.1:8600
}
EOF

And add a file to /etc/resolver (cluster.local) which points to your coreDNS
echo -e "nameserver 127.0.0.1\nport 53" | sudo tee /etc/resolver/cluster.local > /dev/null

I'm sorry to bother you with this, DNS was not my first thought :)

[xinix00]

I got one small other question. It still takes some time to load the first document (in the order of 300ms). I could make my processes warm up the connection first.

            using var rawSession = _documentStore.OpenAsyncSession();
            var result = await rawSession.LoadAsync<object>("not-existing");

this is what I do now, do you have a better suggestion on what to load to make it warm up?

[ppekrol]

Since you need to establish a connection then you can call any endpoint, maybe essential statistics are enough?

await store.Maintenance.SendAsync(new GetEssentialStatisticsOperation());