What are the requests that Maven 3.x sends when deploying artifacts?

The following crudely describes the typical requests made by Maven 3.0.4 during a single module artifact deployment, using maven-deploy-plugin.

Generally

• Maven requests sha1 first and only requests md5 if sha1 not found
• Maven doesn't stop if maven-metadata.xml cannot be retrieved due to 404, it just doesn't merge it
• If GAV maven-metadata.xml cannot be retrieved for a SNAPSHOT artifact, Maven explicitly requests non-timestamped artifacts, like ${artifactid}-${version}-SNAPSHOT.pom, instead of a explicit timestamped version
• Maven deploys main artifact first, the pom last
• other than sha1 and maven-metadata case above, Maven stops if it receives any 4xx or 5xx response

Regular Artifact

SNAPSHOT, NOT A REDEPLOY

-- get GAV maven-metadata.xml ( 404)
-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- put other artifacts + hashes (201)
-- get GA maven-metadata.xml (404)
-- put GAV maven-metadata.xml + hashes (201)
-- put GA maven-metadata.xml + hashes (201)

SNAPSHOT, REDEPLOY

-- get GAV maven-metadata.xml (200) + sha1
-- put main artifact + hashes , timestamped based on previous metadata (201)
-- put pom + hashes (201), timestamped based on previous metadata
-- put other artifacts + hashes, timestamped based on previous metadata (201)
-- get GA maven-metadata.xml + sha1 (200), if sha1 404, then request md5
-- put GAV maven-metadata.xml + hashes (201) , mod based on retrieved metadata
-- put GA maven-metadata.xml + hashes (201) , mod based on retrieved metadata

RELEASE, NOT A REDEPLOY

-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- put attached other artifacts + hashes (201)
-- get GA maven-metadata.xml (404)
-- put GA maven-metadata.xml + hashes (201)

RELEASE, REDEPLOY ( repo allows release redeploy )

-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- put attached other artifacts + hashes (201)
-- get GA maven-metadata.xml (200) + sha1, if sha1 404, then request md5
-- put GA maven-metadata.xml + hashes (201)

Maven Plugin Artifact

SNAPSHOT, NOT A REDEPLOY

-- get GAV maven-metadata.xml ( 404)
-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- get GA maven-metadata.xml (404)
-- get G maven-metadata.xml (404)
-- put GAV maven-metadata.xml + hashes (201)
-- put GA maven-metadata.xml + hashes (201)
-- put G maven-metadata.xml + hashes (201)

SNAPSHOT, REDEPLOY

-- get GAV maven-metadata.xml (200) + hash
-- put main artifact + hashes , timestamped based on previous metadata (201)
-- put pom + hashes (201), timestamped based on previous metadata
-- get GA maven-metadata.xml + sha1 (200), if sha1 404, then request md5
-- get G maven-metadata.xml + sha1 (200), if sha1 404, then request md5
-- put GAV maven-metadata.xml + hashes (201)
-- put GA maven-metadata.xml + hashes (201)
-- put G maven-metadata.xml + hashes (201)

RELEASE, NOT A REDEPLOY

-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- get GA maven-metadata.xml (404)
-- get G maven-metadata.xml (404)
-- put GA maven-metadata.xml + hashes (201)
-- put G maven-metadata.xml + hashes (201)

RELEASE, REDEPLOY ( repo allows release redeploy )

-- put main artifact + hashes (201)
-- put pom + hashes (201)
-- get GA maven-metadata.xml (201) + sha1, if sha1 404, then request md5
-- get G maven-metadata.xml (201) + sha1, if sha1 404, then request md5
-- put GA maven-metadata.xml + hashes (201)
-- put G maven-metadata.xml + hashes (201)