Small adjustment to portal_bridge + docs update (#2110)

fluffy/docs/the_fluffy_book/docs/history-content-bridging.md

@@ -9,12 +9,16 @@
 Run a Portal client with the Portal JSON-RPC API enabled, e.g. fluffy:
 
 ```bash
-./build/fluffy --rpc
+./build/fluffy --rpc --storage-capacity:0
 ```
 
+> Note: The `--storage-capacity:0` option is not required, but it is added here
+for the use case where the node its only focus is on gossiping content from the
+`portal_bridge`.
+
 #### Step 2: Run an EL client
 
-The portal_bridge needs access to the EL JSON-RPC API, either through a local
+The `portal_bridge` needs access to the EL JSON-RPC API, either through a local
 Ethereum client or via a web3 provider.
 
 #### Step 3: Run the Portal bridge in history mode
@@ -27,6 +31,20 @@ WEB3_URL="http://127.0.0.1:8546" # Replace with your provider.
 ./build/portal_bridge history --web3-url:${WEB3_URL}
 ```
 
+Default the portal_bridge will run in `--latest` mode, which means that only the
+latest block content will be gossiped into the network.
+
+The portal_bridge also has a `--backfill` mode which will gossip pre-merge blocks
+from `era1` files into the network. Default the bridge will audit first whether
+the content is available on the network and if not it will gossip it into the
+network.
+
+E.g. run latest + backfill with audit mode:
+```bash
+WEB3_URL="http://127.0.0.1:8546" # Replace with your provider.
+./build/portal_bridge history --latest:true --backfill:true --audit:true --era1-dir:/somedir/era1/ --web3-url:${WEB3_URL}
+```
+
 ### Seeding post-merge history data with the `beacon_lc_bridge`
 
 The `beacon_lc_bridge` is more of a standalone bridge that does not require access to a full node with its EL JSON-RPC API. However it is also more limited in the functions it provides.

fluffy/tools/portal_bridge/portal_bridge_conf.nim

@@ -116,7 +116,7 @@ type
       audit* {.
         desc:
           "Run pre-merge backfill in audit mode, which will only gossip content that if failed to fetch from the network",
-        defaultValue: false,
+        defaultValue: true,
         name: "audit"
       .}: bool
 

fluffy/tools/portal_bridge/portal_bridge_history.nim

@@ -289,8 +289,8 @@ proc runLatestLoop(
     let elapsed = t1 - t0
     if elapsed < newHeadPollInterval:
       await sleepAsync(newHeadPollInterval - elapsed)
-    else:
-      warn "Block gossip took longer than the poll interval"
+    elif elapsed > newHeadPollInterval * 2:
+      warn "Block gossip took longer than slot interval"
 
 proc gossipHeadersWithProof(
     portalClient: RpcClient,