add more documentation

Author: jonastheis

sequencer-migration/README.md

@@ -1,5 +1,4 @@
 # Scroll Sequencer Migration 
-
 This module contains documentation and scripts for Scroll's sequencer migration from `l2geth` to rollup node (RN) aka `l2reth`.
 
 ### Risks 
@@ -25,11 +24,21 @@ The high-level flow of the transition will look like this:
 9. Turn on `l2geth` sequencingx
 
 ### Testing locally
+To test locally run the test `docker_test_migrate_sequencer` and execute the `migrate-sequencer.sh` script.
 ```bash
 # this test runs for ~60 seconds and starts with l2geth sequencing and expects all nodes to reach the same block at block number 120.
 RUST_LOG=info,docker-compose=off cargo test --package tests --test migrate_sequencer -- docker_test_migrate_sequencer --exact --show-output
 
 source local.env
-./migrate-sequencer.sh
+./migrate-sequencer.sh <blocks_to_produce>
+
+# if necessary, reset l2geth block height and start sequencing on l2geth.
+./revert-l2geth-to-block.sh <block_number>
 ```
 
+**Simulating failure case**: 
+- To simulate the case where `l2reth` produces invalid blocks we can adjust to `--builder.gaslimit=40000000` in `launch_rollup_node_sequencer.bash`. This will produce a block with a too big jump of the gas limit and `l2geth` will reject it. In a simulation we can then "revert" `l2geth` to its latest block and start sequencing on `l2geth` again.
+- Continuing on the above case we can fabricate a L2 reorg by simply resetting to any previous block. For all `l2geth` nodes the reorg will be shallow (ie before the invalid `l2reth` blocks) and for `l2reth` it will be deeper (ie all `l2reth` produced blocks + reset to previous block).
+
+TODO: how to run with Docker
+

tests/src/utils.rs

@@ -48,7 +48,7 @@ pub async fn miner_stop(provider: &NamedProvider) -> Result<()> {
 /// * `Ok(())` if all nodes reach the target block within the timeout
 /// * `Err` if timeout is reached or any provider call fails
 pub async fn wait_for_block(nodes: &[&NamedProvider], target_block: u64) -> Result<()> {
-    let timeout_duration = Duration::from_secs(30);
+    let timeout_duration = Duration::from_secs(60);
     let timeout_secs = timeout_duration.as_secs();
 
     tracing::info!(